Statistics Questions

Suppose the results indicate that the null hypothesis should not be rejected thus it is possible that a type II error has been committed Given the type of error made in this situation what could researchers do to reduce the risk of this error Choose a 01 significance level instead of a 05 significance level Increase the sample size

The p value for a hypothesis test turns out to be 0 034895 At a 6 level of significance what is the proper decision O Fail to reject Ho Reject Ho

You are performing a hypothesis test of a single population mean using a Student s t distribution The data are not from a simple random sample Can you accurately perform the hypothesis test No the Student s t distribution is appropriate only for testing claims based on two samples No for a hypothesis test the data are assumed to be from a simple random sample No the Student s t distribution is appropriate only for testing claims about proportions No for a hypothesis test the normal distribution should always be used

The IQ test is constructed so that Full Scale IQ scores follow a normal distribution with a mean of 100 and a standard deviation of 15 The dean of a school believes their students are smarter than the national average and wants to use it the intelligence of the students as a marketing tool to bring students to the school A researcher is hired to conduct a study to determine whether the schools students have on average higher Full Scale IQs than the population A random sample of 100 people from the school were given the IQ test and were found to have an average Full Scale IQ of 105 Which hypothesis test should be used to determine whether the mean Full Scale IQ score of the schools students is higher than the national average CAM Ot test for the population proportion Ot test for the population mean Oz test for the population mean z test for the population proportion

went A Age 12 12 to 15 16 to 24 25 to 64 65 Totals Event B Vaccinated Not Vaccinated 124 873 47 793 946 6 424 266 10 214 213 17 950 590 20 983 450 38 934 040 100 514 773 72 858 178 173 372 951 42 397 381 13 507 909 55 905 290 167 411 883 165 357 696 332 769 579 Totals 47 918 479 16 638 479 Simple Probabilities P Vaccinated P Not Vaccinated P 12 P 12 to 15 P 16 to 24 P 25 to 64 P 65 Joint Probabilities A And B P Vaccinated and 65 P Vaccinated and 12 to 15 P Not Vaccinated and 16 to 24 P Not Vaccinated and 12 Addition Rule A Or B P Vaccinated or 25 P Not Vaccinated or 65 P Vaccinated or 64 P Not Vaccinated or 16 to 24 Conditional Probabilities A given B P Vaccinated 12 to 15 P Vaccinated 16 to 24 P Not Vaccinated 65

More than 82 of workers got their job through networking Express the null and alternative hypotheses in symbolic form for this claim Ho p HA P

Event A Age 12 12 to 15 16 to 24 25 to 64 65 Event B Vaccinated 124 873 6 424 266 17 950 590 100 514 773 42 397 381 Not Vaccinated 47 793 946 10 214 213 20 983 450 72 858 178 13 507 909 Totals

Suppose that a recent article stated that the mean time spent in jail by a first time convicted burglar is 3 7 years A study was then done to see if the mean time has decreased in recent years A random sample of 38 first time convicted burglars was recently selected The mean length of time in jail from the survey was 2 7 years Suppose that it is somehow known that a the population standard deviation is 2 years Conduct a hypothesis test at the a 0 05 significance level to determine if the mean length of jail time has decreased Assume the distribution of the jail times is approximately normal Ho H Select an answer P value years years Enter the correct symbol and value round your answer to 4 place values

ou are performing a right tailed test with test statistic z 3 09 find the p value to 4 decima places

You are performing a left tailed test with test statistic z 2 6 find the p value accurate to 4 decimal places p value

Question You Are Considering Buying An Industrial Equipment Whose Price 260000 The You are considering buying an industrial equipment whose price 260000 The equipment is expected to earn an annual revenue of 150 000 The equipment will be depreciated under MACRS as a five year recovery property The equipment will be used for seven years at the end of which time you can sell it for 50 000 Your company s marginal tax rate is 35 over the project period Perform the following a Determine the net after tax cash flows for each period over the project life b Net present worth assuming company MARR 15 c Annual equivalent cash flow company MARR 15 d IRR of the project

At most 79 of Internet users pay bills online Express the null and alternative hypotheses ir symbolic form for this claim Ho p O II

A commonly cited work week hours for an employee is 36 hours A company samples 200 employees and find an average work week hours of 47 hours with a standard deviation of 11 hours Which of the following is the correct set of hypotheses for testing if the average work week hours of an employee of this company is different than the commonly cited standard of 36 hours Ho H 36 HA X 47 Ho H 36 HA 36 HA H 36 Ho x 36 Ho x 47 HA H 36 Ho H 36 HA 36

3x 3x The area of the unshaded region in the square above i 3x y 3x y O 9x y2 O 3x 3x y y 3x y O 3x 3x y y 3x y O 3x y 3x y

A Which of the following could be an equation of the line graphed in the xy plane ab 0y 1 x 1 0y x 1 Oy 2x 1 Oy 2x 1

Of x 1 x 1 Of x x 1 S i 3 7 4 Some values of the function f x are shown above Which of the following could be the definition of f o S

A survey of working adults is described in an online article The article states Workers with a college education had a significantly increased chance of getting a pay raise in the past year with 35 percent of the group seeing an increase compared with 18 percent of those with some college and 17 percent of those with high school diplomas or less Suppose that the three samples college degree some college high school diploma or less were independently selected representative samples and that the sample size for each sample was 500 USE SALT a Use the given information and the five step process for estimation problems EMC3 to calculate a 95 confidence interval for the difference in the proportion who received raises for those with a college degree and those with a high school diploma or less Use College Degree High School Diploma or Less Enter your answer using interval notation Round your numerical values to four values Interpret the interval We are 95 confident that the true difference in the proportion of working adults with college degrees who saw a pay raise and the same proportion for those with a high school diploma or less falls within this interval The bounds of the interval suggest the proportion was higher for those with a college degree b Use the given information and the five step process for estimation problems EMC3 to calculate a 95 confidence interval for the difference in the proportion who received raises for those with some college and those with a high school diploma or less Use Some College High School Diploma or Less Enter your answer using interval notation Round your numerical values to four values Interpret the interval We are 95 confident 0 that the true difference in the proportion of working adults with some college education who saw a pay raise and the same proportion for those this interval The bounds of the interval suggest the proportion was higher for those with some college education X with a high school diploma or less falls within om Biki Foru E Projec 2 Scre 023 0

What impact does fast food consumption have on various dietary and health characteristics A research article reported the accompanying summary statistics on daily calorie intake in calories per day for a representative sample of teens who do not typically eat fast food and a representative sample of teens who do eat fast food H Sample Do not eat fast food Eat fast food P value USE SALT Sample Sample Sample Standard Size Mean Deviation 661 416 2 254 2 638 Find the test statistic Round your answer to two decimal places 1 511 Is there convincing evidence that the mean calorie intake for teens who typically eat fast food is greater than the mean intake for those who don t by more than 150 calories per day Test the relevant hypotheses using a significance level of a 0 05 Use for teens who typically eat fast food and for teens who don t typically eat fast food State the appropriate null and alternative hypotheses in calories per day Enter for as needed Ho 1 132 MY NOTES Use technology to find the P value Round your answer to four decimal places State the conclusion in the problem context We reject Ho There is convincing evidence that the mean calorie intake for teens who typically eat fast food is greater than the mean intake for those who don t by more than 150 calories per day calorie intake for teens who typically eat fast food is greater than the mean intake for those who don t by more legreewor Project fo 1 pptx 17 PLAY omparecon RP1 pdf Biki Bike Pro Forum 1 mp Project C ppt Screensho 023 0 46 Pr Screenshot 023 0 01 PM

a 95 large sample confidence interval for the proportion of college graduates who experience information overload Hint This is a one sample confidence interval Enter your answer using interval notation Round your numerical values to four decimal places 0 1308 0 1878 Interpret the interval There is a 95 chance that the true proportion of college graduates who experience information overload falls directly in the middle of this interval We are 95 confident that the true difference in the proportion of college graduates who experience information overload and this proportion for people who have never attended college falls within this interval There is a 95 chance that the true difference in the proportion of college graduates who experience information overload and this proportion for people who have never attended college falls directly in the middle of this interval O We are 95 confident that the true proportion of college graduates who experience information overload falls within this interval We are 95 confident that the true proportion of people who have never attended college who experience information overload falls within this interval b Construct a 95 large sample confidence interval for the proportion of people who have never attended college who experience information overload Enter your answer using interval notation Round your numerical values to four decimal places 0 X Interpret the interval There is a 95 chance that the true proportion of college graduates who experience information overload falls directly in the middle of this interval We are 95 confident that the true difference in the proportion of college graduates who experience information overload and this proportion for people who have never attended college falls within this interval There is a 95 chance that the true difference in the proportion of college graduates who experience information overload and this proportion for people who have never attended college falls directly in the middle of this interval Lovnorience information overload falls within this intonal 02 SC 023 C

Yes O No parts a and b overlap What does this suggest about the two population proportions This suggests that the two population proportions might be the same O This suggests that the two population proportions might be different from each other d Construct a 95 large sample confidence interval for the difference in the proportions who have experienced information overload for college graduates and for people wh have never attended college Use P P where p is the true proportion of college graduates who experience information overload and p is the true proportion of thos have never attended college who experience information overload Enter your answer using interval notation Round your numerical values to four decimal places 0 5819 0 4247 X Interpret the interval We are 95 confident that the true difference in the proportion of college graduates who experience information overload and the same proportion for those who ha never attended college falls within this interval The bounds of the interval suggest the proportion is higher for those who have never attended college e Is the interval in part d consistent with your answer in part c Explain Yes both interpretations indicate that there might not be a significant difference in the proportions of those who attended college and experience information overloa and those who never attended college and experience information overload O Yes both interpretations indicate that there might be a significant difference in the proportions of those who attended college and experience information overload ar those who never attended college and experience information overload No part c indicates that there might be a significant difference in the proportions of those who attended college and experience information overload and those who never attended college and experience information overload while part d indicates that there might not be a significant difference

Participants in independent representative samples of teens and parents of teens were asked if they check their phone for messages as soon as they wake up Of the 750 teens surveyed 46 said yes and of the 1 050 parents of teens surveyed 22 said yes Do the data provide convincing evidence that the proportion of parents of teens who check their phone for messages as soon as they wake up is less than the proportion of teens who check for messages as soon as they wake up Test the relevant hypotheses using a significance level of 0 05 Let p be the population proportion of parents of teens who check their phone for messages as soon as they wake up and p be the population proportion of teens who check their phone for messages as soon as they wake up State the appropriate null and alternative hypotheses Enter for as needed Ho H P1 P2 USE SALT P P2 Find the test statistic Round your answer to two decimal places Use technology to find the P value Round your answer to four decimal places P value State your conclusion Fail to reject Ho We do not have convincing evidence that the proportion of parents of teens who check their phone for messages as soon as they wake up is less than the proportion of teens who check for messages as soon as they wake up Reject Ho We do not have convincing evidence that the proportion of parents of teens who check their phone for messages as soon as they wake up is less than the proportion of teens who check for messages as soon as they wake up O Reject Ho We have convincing evidence that the proportion of parents of teens who check their phone for messages as soon as they wake up is less than the proportion of teens who check for messages as soon as they wake up o convincing evidence that the proportion of parents of teens who check their phone for messages as soon as they wake up is less than the MALAY Project fo 1 pptx omparecon RP1 pdf Biki Bike Pro Forum 1 mp Project C ppt Screenshot 023 0 46 PM Screenshot 023 0 01 PM

Many people now turn to the Internet to get information on health related topics A research article used Flesch reading ease scores a measure of reading difficulty based on factors such as sentence length and number of syllables in the words used to score pages on Wikipedia and on WebMD Higher Flesch scores correspond to more difficult reading levels The paper reported that for a representative sample of health related pages on Wikipedia the mean Flesch score was 26 6 and the standard deviation of the Flesch scores was 14 7 For a representative sample of pages from WebMD the mean score was 43 6 and the standard deviation was 19 6 Suppose that these means and standard deviations were based on samples of 40 pages from each site Is there convincing evidence that the mean reading level for health related pages differs for Wikipedia and WebMD Test the relevant hypotheses using a significance level of a 0 05 Use for Wikipedia and for WebMD State the appropriate null and alternative hypotheses Enter for as needed 12 Ho USE SALT H H1 H2 X The form of your answer may be incorrect Possible forms might include Find the test statistic Round your answer to two decimal places 4 5 X Use technology to find the P value Round your answer to four decimal places P value 0 MY NOTES State the conclusion in the problem context We reject Ho There is not convincing evidence that the mean reading level for health related pages differs for Wikipedia and WebMD There is convincing evidence that the mean reading level for health related pages differs for Wikipedia and WebMD PRACTICE ANOTHER

A research article reported that for a random sample of 850 meal purchases made at fast food chain A the mean sodium content was 1 682 mg and the standard deviation was 829 mg For a random sample of 2 106 meal purchases made at fast food chain B the mean sodium content was 1 476 mg and the standard deviation was 813 mg Based on these data is it reasonable to conclude that there is a difference in mean sodium content for meal purchases at fast food chain A and meal purchases at fast food chain B Use a 0 05 Use for fast food chain A and for fast food chain B State the appropriate null and alternative hypotheses in mg Enter for as needed 0 0 Ho USE SALT H Find the test statistic Round your answer to two decimal places Use technology to find the P value Round your answer to four decimal places P value MY NOTES State the conclusion in the problem context We fail to reject Ho It is reasonable to conclude that there is a difference in mean sodium content for meal purchases at fast food chain A and meal purchases at fast food chain B We reject Ho It is not reasonable to conclude that there is a difference in mean sodium content for meal purchases at fast food chain A and meal purchases at fast food chain B O We reject Ho It is reasonable to conclude that there is a difference in mean sodium content for meal purchases at fast food chain A and meal purchases at fast food chain B It is not reasonable to conclude that there is a difference in mean sodium content for meal purchases at fast food chain A and meal purchases at fast food Hm fail te roiect H Project forur 1 pptx Th omparecontr RP1 pdf Biki Bike Pro Forum 1 mp4 Project C ppt Screensho 023 0 46 F Screensha 023 0 01 F

Many people believe that they experience information overload in today s digital world A report describes a survey in which people were asked if they feel overloaded by information Suppose in a representative sample of 634 college graduates 101 indicated that they suffered from information overload while 118 people in an independent representative sample of 496 people who had never attended college said that they suffered from information overload USE SALT a Construct a 95 large sample confidence interval for the proportion of college graduates who experience information overload Hint This is a one sample confidence interval Enter your answer using interval notation Round your numerical values to four decimal places 0 1323 0 1895 X MY NOTES Interpret the interval There is a 95 chance that the true proportion of college graduates who experience information overload falls directly in the middle of this interval We are 95 confident that the true difference in the proportion of college graduates who experience information overload and this proportion for people who have never attended college falls within this interval There is a 95 chance that the true difference in the proportion of college graduates who experience information overload and this proportion for people who have never attended college falls directly in the middle of this interval o We are 95 confident that the true proportion of college graduates who experience information overload falls within this interval We are 95 confident that the true proportion of people who have never attended college who experience information overload falls within this interval b Construct a 95 large sample confidence interval for the proportion of people who have never attended college who experience information overload Enter your answer using interval notation Round your numerical values to four decimal places 20

Do children diagnosed with attention deficit hyperactivity disorder ADHD have smaller brains than children without this condition This question was the topic of a research study Brain scans were completed for a representative sample of 152 children with ADHD and a representative sample of 139 children without ADHD Summary values for total cerebral volume in milliliters are given in the following table Children with ADHD n Children without ADHD 139 USE SALT Ha M1 H X 152 1 058 4 117 9 S 1 104 8 111 1 Is there convincing evidence that the mean brain volume for children with ADHD is smaller than the mean for children without ADHD Test the relevant hypotheses using a 0 05 level of significance Use for children with ADHD and for children without ADHD State the appropriate null and alternative hypotheses in millimeters Enter for as needed Ho 1 Find the test statistic Round your answer to two decimal places Use technology to find the P value Round your answer to four decimal places P value E Pr 02 S 1033

What impact does fast food consumption have on various dietary and health characteristics A research article reported the accompanying summary statistics on daily calorie intake in calories per day for a representative sample of teens who do not typically eat fast food and a representative sample of teens who do eat fast food Sample Do not eat fast food Eat fast food LUSE SALT Sample Sample Size Mean calories per day 669 411 2 253 2 632 Sample Standard Deviation 1 517 MY 1 139 Construct a 95 confidence interval estimate of the difference in mean daily calorie intake in calories per day for teens who do eat fast food on a typical day and those who do not Use Eat fast food Do not eat fast food Use technology to calculate your critical value Enter your answer using interval notation Round your numerical values to two decimal places Interpret the interval O We are 95 confident that the true difference in mean calorie intake for teens who do eat fast food and the mean calorie intake for teens who do not eat fast food falls within this interval The bounds of the interval suggest the two means could be equal X Projec 1 pp ompare RP1 F Biki Bike Forum 1 Project C Screen

The authors of a certain paper describe a study to evaluate the effect of mobile phone use by taxi drivers in Greece Fifty taxi drivers drove in a driving simulator where they were following a lead car The drivers were asked to carry on a conversation on a mobile phone while driving and the following distance the distance between the taxi and the lead car was recorded The sample mean following distance was 3 80 meters and the sample standard deviation was 1 17 meters USE SALT a Construct a 95 confidence interval in meters for u the population mean following distance while talking on a mobile phone for the population of taxi drivers Use technology to calculate your critical value Enter your answer using interval notation Round your numerical values to three decimal places m MY NOTES Interpret the interval We are 95 confident that the sample mean following distance while talking on a mobile phone for the taxi drivers in the study falls within this interval There is a 95 chance that the actual mean following distance while talking on a mobile phone for the population of taxi drivers falls directly in the middle of this interval o We are 95 confident that the actual following distance while talking on a mobile phone for the population of taxi drivers falls within this interval There is a 95 chance that the sample mean following distance while talking on a mobile phone for the taxi drivers in the study falls within this interval The following distance while talking on a mobile phone is in the interval for 95 of the population of taxi drivers b What assumption must be made in order to generalize this confidence interval to the population of all taxi drivers in Greece o We need to assume that taxi drivers used in the study are representative of all taxi drivers in Greece We need to assume that taxi drivers used in the study are representative of all drivers who have used the simulator We need to assume that taxi drivers used in the study are all driving the same make and model car that taxi drivers used in the study are all using the same mobile phone

When the tissue around teeth becomes inflamed the tissue bleeds more easily and this is an indication of gum disease The severity of bleeding can be measured by a bleeding score that is determined by the percentage of teeth for which bleeding occurs when the tissue surrounding the tooth is probed In terms of dental health lower bleeding scores are better than higher bleeding scores The authors of a paper wondered if the nutrients found in kiwis might reduce bleeding To investigate 25 adult participants agreed to consume 2 kiwis a day for a period of 2 months A bleeding score was recorded for each participant at the beginning of the study period and again after 2 months of kiwi consumption Because this resulted in paired samples differences in bleeding scores before after were analyzed It was reported that the sample mean difference was x 6 63 and the standard deviation of the differences was s 11 10 Assuming that the 25 study participants can be considered as representative of the population of adults is there convincing evidence that the mean bleeding score is lower after 2 months of kiwi consumption Test the relevant hypotheses using a significance level of 0 01 Use for before kiwi consumption for after kiwi consumption and d USE SALT State the appropriate null and alternative hypotheses in minutes Enter for as needed Ho Find the test statistic Round your answer to two decimal places Use technology to find the P value Round your answer to four decimal places P value State the conclusion in the problem context Reject Ho We have convincing evidence that the mean bleeding score is lower after 2 months of kiwi consumption MY NOTES Fail to reject Ho We do not have convincing evidence that the mean bleeding score is lower after 2 months of kiwi consumption Fail to reject Ho We have convincing evidence that the mean bleeding score is lower after 2 months of kiwi consumption

Do children diagnosed with attention deficit hyperactivity disorder ADHD have smaller brains than children without this condition This question was the topic of a research study Brain scans were completed for a representative sample of 152 children with ADHD and a representative sample of 139 children without ADHD Summary values for total cerebral volume in cubic milliliters are given in the following table Children with ADHD Children without ADHD USE SALT Interpret the interval We are 95 confident within n O X 139 152 1 058 5 116 3 S 1 104 7 Construct a 95 confidence interval estimate of the difference in mean brain volume in mL for children with and without ADHD Use With ADHD Without ADHD Use technology to calculate your critical value Enter your answer using interval notation Round your numerical values to two decimal places ML3 111 7 that the true difference in mean brain volume for children with ADHD and the mean brain volume for children without ADHD falls this interval The bounds of the interval suggest the mean brain volume is higher for those without ADHD

The author of the article wanted to know if these data support the claim that students who participated in the chess program tend to achieve higher memory scores after completion of the program Carry out a hypothesis test to answer this question Use 0 05 Use for pre test for post test and 1 State the appropriate null and alternative hypotheses Enter for as needed Ho Md 0 H Md 0 Find the test statistic Round your answer to two decimal places Use technology to find the P value Round your answer to four decimal places P value State the conclusion in the problem context We reject Ho The data support the claim that students who participated in the chess program tend to achieve higher memory scores after completion of the program We fail to reject Ho The data do not support the claim that students who participated in the chess program tend to achieve higher memory scores after completion of the program We fail to reject Ho The data support the claim that students who participated in the chess program tend to achieve higher memory scores after completion of the program We reject Ho The data do not support the claim that students who participated in the chess program tend to achieve higher memory scores after completion of the program Pr 02

In a study of memory recall 8 students from a large psychology class were selected at random and given 10 minutes to memorize a list of 20 nonsensical words Each was asked to list as many of the words as he or she could remember both 1 hour and 24 hours later The data are as shown in the accompanying table Student 1 hour later 24 hours later Submit Answer 1 USE SALT 2 3 4 14 13 19 7 13 9 9 4 14 5 6 5 10 5 7 8 16 17 Use these data to estimate the difference in mean number of words remembered after 1 hour and after 24 hours Use a 90 confidence interval Use Hd 1 hour later 24 hours later Use a table or SALT Round your answers to two decimal places words 11 13 MY NOTE

A study investigated whether price affects people s judgment Twenty people each tasted six cabernet sauvignon wines and rated how they liked them on a scale of 1 to 6 Prior to tasting each wine participants were told the price of wine Of the six wines tasted two were actually the same wine but for one tasting the participant was told that the wine cost 10 per bottle and for the other tasting the participant was told that the wine cost 90 per bottle The participants were randomly assigned to either taste the wine claimed to be 90 first and the wine claimed to be 10 second or the 10 wine first and the 90 wine second Differences were calculated by subtracting the rating for the tasting in which the participant thought the wine cost 10 from the rating for the tasting in which the participant thought the wine cost 90 The differences that follow are consistent with summary quantities given in the paper Difference in Rating 90 10 4321 0 0 3 2 USE SALT 0 Interpret the interval 2 3 3 3 1 4 1 1 1 1 1 Use the data given above to construct a 90 confidence interval for the difference in mean rating assigned to the wine when the cost is described as 90 and when the cost is described as 10 Use 90 10 Enter your answer using interval notation Round your numerical values to four decimal places We are 90 confident that the true difference in mean rating assigned to the wine when the cost is described as 90 and when the cost is described as 10 falls within this interval The bounds of the interval suggest the mean rating was higher when the cost is described as 90

PREVIOUS ANSWERS hr The authors of a paper were interested in estimating the mean time that patients who broke a hip had to wait for surgery before and after the opening of a new hospital facility They reported that for a representative sample of 405 patients seen at this hospital before the new facility was opened the mean wait time for surgery was 31 1 hours and the standard deviation of wait times was 27 0 hours For a representative sample of 214 patients seen after the new facility was opened the mean wait time for surgery was 28 7 hours and the standard deviation of wait times was 16 2 hours LUSE SALT PECKSTAT3 12 2 033 S a Construct a 95 confidence interval for the mean wait time in hours of patients seen before the new facility was opened Enter your answer using interval notation Round your numerical values to three decimal places Interpret the previously found interval We are 95 confident that the true mean wait time of patients in this sample who were seen before the new facility was opened falls within this interval We can say that 95 of all patient wait times before the new facility was opened fall within this interval There is a 95 chance that the true mean wait time of patients in this sample who were seen before the new facility was opened falls within this interval o We are 95 confident that the true mean wait time of patients seen before the new facility was opened falls within this interval O There is a 95 chance that the true mean wait time of patients seen before the new facility was opened falls within this interval hr MY NOTES b Construct a 95 confidence interval for the mean wait time in hours of patients seen after the new facility was opened Enter your answer using interval notation Round your numerical values to three decimal places Interpret the previously found interval if untianto in this cample who were seen after the new facility was opened falls within this interval Proj 1 ompa RF Biki B Forur Projec Scr 023 0 552 Scre 023 0

Suppose an article states People ages 35 to 54 were the least likely group to report buckling up in the back seat Seventy four percent of this group reported always buckling up in the back seat compared with 78 of adults age 18 to 34 Suppose that it is reasonable to regard the sample of people 18 to 34 years old and the sample of people of age 35 to 54 as independent samples that are representative of these two age groups and that both sample sizes were 50 Is there convincing evidence that the proportion who always buckle up in the back seat is different for people of age 18 to 34 and people of age 35 to 54 Test the appropriate hypotheses using a significance level of 0 05 Let p be the population proportion of people age 18 to 34 who always buckle up in the back seat and p be the population proportion of people age 35 to 54 who always buckle up in the back seat State the appropriate null and alternative hypotheses Enter for as needed P1 P2 Ho USE SALT P P2 Find the test statistic Round your answer to two decimal places PRACTICE ANOTHER Use technology to find the P value Round your answer to four decimal places P value State your conclusion to 51

To determine if chocolate milk is as effective as other carbohydrate replacement drinks 10 trained cyclists performed an intense workout followed by a drink and a rest period At the end of the rest period each cyclist performed a 40 km timed trial in which they were instructed to try to cycle this distance as fast as possible The time to completion was then recorded Each cyclist completed the entire regimen on two different days On one day the drink provided was chocolate milk and on the other day the drink provided was a carbohydrate replacement drink Data are given in the table below Cyclist Chocolate Milk Carbohydrate Replacement LUSE SALT 1 Time to Complete Trial in minutes 45 78 79 81 82 82 84 87 87 86 89 93 396 99 101 2 74 75 3 77 73 75 76 84 6 Find the test statistic Round your answer to two decimal places ICE ANOTHER 10 Is there evidence that the mean time to complete the trial is shorter after chocolate milk than after a carbohydrate replacement drink Use a significance level of a 0 05 Use for chocolate milk for the carbohydrate replacement and 2 State the appropriate null and alternative hypotheses in minutes Enter for as needed Ho M H2 H H1 H Use technology to find the P value Round your answer to four decimal places P value Projec 1 pp ompar RP1 Biki Bi Forum Projec Scr 023 Sc 023

The National Sleep Foundation surveyed representative samples of adults in six different countries to ask questions about sleeping habits t Each person in a representative sample of 250 adults in each of these countries was asked how much sleep they get on a typical work night For the United States the sample mean was 391 minutes and for Mexico the sample mean was 426 minutes USE SALT MY NOTES The report also gave data for representative samples of 250 adults in Canada and 250 adults in England The sample mean amount of sleep on a work night was 423 minutes for the Canada sample and 409 minutes for the England sample Suppose that the sample standard deviations were 34 minutes for the Canada sample and 43 minutes for the England sample PRACTICE ANOTHER minutes a Construct a 95 confidence interval estimate of the difference in the mean amount of sleep in minutes on a work night for adults in Canada and adults in England Use Canada England Use technology to calculate your critical value Enter your answer using interval notation Round your numerical values to three decimal places X Interpret the interval There is a 95 chance that the sample difference in the mean amount of sleep on a work night for adults studied in Canada and adults studied in England falls within this interval We are 95 confident that the true difference in the mean amount of sleep on a work night for adults in Canada and adults in England falls within this interval There is a 95 chance that the true difference in the mean amount of sleep on a work night for adults in Canada and adults in England falls directly in the middle of this interval We are 95 confident that the sample difference in the mean amount of sleep on a work night for the adults studied in Canada and adults studied in England falls within this interval There is a 95 chance that the sample difference in the mean amount of sleep on a work night for adults studied in Canada and adults studied in England falls directly in the middle of this interval ot of cloon on a work night for the two countries

A manufacturer of college textbooks is interested in estimating the strength of the bindings produced by a particular Dindi ing force required to pull the pages of a book from its binding If this force is measured in pounds what is the minimum number of books that should be tested to estimate the average force required to break the binding with a margin of error of 0 1 pounds with 95 confidence Assume that a is known to be 0 9 pounds Round your answer up to the nearest integer Enter an exact number Need Help USE SALT Submit Answer books Read It DETAILS Master It PREVIOUS ANSWERS PECKSTAT3 12 3 042 S MY NOTES PRACTICE ANOTHER 5 5 5 Points A paper summarizes data from 61 young children living in a particular county in a particular state who had their blood lead levels measured as part of a routine healthcare visit The comple mean blood level was 16 g dL and the sample standard deviation was 6 7 g dL Suppose that it is reasonable to regard this sample as representative of young children that the mean blood lead level for young children in this county is greater than 10 g dL Carry out a hypothesis test TA omparec RP1 pc Biki Bike Forum 1 Project Scr 023

eight specimens and the resulting mean and standard deviation were 306 01 newtons and 41 91 newtons respectively Assuming that it is reasonable to believe that breaking force Tee replacements to secure an artificial joint in place The force required to break an acrylic bone cement bond was measured for has a distribution that is approximately normal use a 95 confidence interval to estimate the mean breaking force for acrylic bone cement in newtons Enter your answer using interval notation Round your numerical values to three decimal places Submit Answer N USE SALT

A government agency reported that in 2020 6 0 of people with a bachelor s degree and 9 5 of people with a high school diploma but no college were unemployed Suppose that the reported percentages were based on independently selected representative samples of 600 people with a bachelor s degree and 600 people with a high school degree but no college It was also reported that 4 4 of those with master s degrees were unemployed in 2020 Suppose that this reported percentage was based on a representative sample of 250 people with master s degrees Use this information to answer the following questions USE SALT PRACTICE ANOTHER a Construct a 99 large sample confidence interval for the difference in the proportion who were unemployed in 2020 for those who have a bachelor s degree and those who have a master s degree Use Bachelor s Degree Master s Degree Enter your answer using interval notation Round your numerical values to four decimal places X Interpret the interval We are 99 confident degree falls within O that the true difference in the proportion of people with a bachelor s degree who are unemployed and this proportion for people with a master s O this interval The bounds of the interval suggest the two proportions could be equal b The following is a 95 large sample confidence interval for the difference in the proportion who were unemployed in 2020 for those who have a bachelor s degree and those who have a high school diploma but no college 0 0652 0 0048 Is the confidence interval from part a wider or narrower than this confidence interval

A student organization uses the proceeds from a soft drink vending machine to finance its activities The price per can was 0 75 for a long time and the mean daily revenue during that period was 75 00 The price was recently increased to 1 00 per can A random sample of n 25 days after the price increase yielded a sample mean daily revenue and sample standard deviation of 70 00 and 4 25 respectively Does this information suggest that the mean daily revenue has decreased from its value before the price increase Test the appropriate hypotheses using 0 05 LUSE SALT State the appropriate null and alternative hypotheses Enter for as needed Ho 75 H 75 Find the test statistic Round your answer to two decimal places Use technology to find the P value Round your answer to four decimal places P value MY NOTES State the conclusion in the problem context We fail to reject Ho We do not have convincing evidence that the mean daily revenue from the soft drink vending machine has decreased from its value before the price increase We reject Ho We do not have convincing evidence that the mean daily revenue from the soft drink vending machine has decreased from its value before the price increase We reject Ho We have convincing evidence that the mean daily revenue from the soft drink vending machine has decreased from its value before the price increase used from its value before the price increase tegreeworks Project for 1 pptx ENDO omparecor RP1 pdf Biki Bike Forum 1 n Project C Scree 023 0

A report on food science states that younger adults are more likely to see foods with genetically modified ingredients as being bad for their health than older adults This statement is based on a representative sample of 175 adult Americans age 18 to 29 and a representative sample of 450 adult Americans age 50 to 64 Of those in the 18 to 29 age group 48 said they believed these foods were bad for their health while only 36 of those in the 50 to 64 age group believed this USE SALT a Are the sample sizes large enough to use the large sample confidence interval to estimate the difference in the population proportions Explain Let p 0 48 and 0 36 n 175 and n 450 where the 1 subscript indicates the age 18 29 group and the 2 subscript indicates the age 50 64 group Since P 84 n 1 P 91 P 162 and n 1 288 all at least 10 the I sample sizes are large enough to use the large sample confidence interval 0 O No b Estimate the difference in the proportion of adult Americans age 18 to 29 who believe the foods made with genetically modified ingredients are bad for their health and the corresponding proportion for adult Americans age 50 to 64 Use a 90 confidence interval Use P P2 Enter your answer using interval notation Round your numerical values to four decimal places c Is zero in the confidence interval Yes are

H A report about how American college students manage their finances includes data from a survey of college students Each person in a representative sample of 793 college students was asked if they had one or more credit cards and if so whether they paid their balance in full each month There were 500 who paid in full each month For this sample of 500 students the sample mean credit card balance was reported to be 825 The sample standard deviation of the credit card balances for these 500 students was not reported but for purposes of this exercise suppose that it was 205 Is there convincing evidence that college students who pay their credit card balance in full each month have a mean balance that is lower than 905 the value reported for all college students with credit cards Carry out a hypothesis test using a significance level of 0 01 USE SALT State the appropriate null and alternative hypotheses in dollars Enter for as needed Ho 905 905 AT3 12 3 049 MI S Find the test statistic Round your answer to two decimal places MY NOTES Use technology to find the P value Round your answer to four decimal places P value PRACTICE ANOTHER State the conclusion in the problem context We reject Ho We do not have convincing evidence that college students who pay their credit card balance in full each month have a mean balance that is lower than 905 We fail to reject Ho We do not have convincing evidence that college students who pay their credit card balance in full each month have a mean balance that is lower than 905 We fail to reject Ho We have convincing evidence that college students who pay their credit card balance in full each month have a mean balance that is lower than 905 egree Proje 1 omp RI Biki Fort I Proj S 02

A report summarizes a survey of people in two independent random samples One sample consisted of 600 young adults age 19 to 35 and the other sample consisted of 200 parents of young adults age 19 to 35 The young adults were presented with a variety of situations such as getting married or buying a house and were asked if they thought that their parents were likely to provide financial support in that situation The parents of young adults were presented with the same situations and asked if they would be likely to provide financial support to their child in that situation The report stated that the proportion of young adults who thought their parents would help with buying a house or renting an apartment for the sample of young adults was 0 37 For the sample of parents the proportion who said they would help with buying a house or renting an apartment was 0 27 Based on these data can you conclude that the proportion of parents who say they would help with buying a house or renting an apartment is significantly less than the proportion of young adults who think that their parents would help Test the appropriate hypotheses using a significance level of 0 05 Let p be the proportion of all parents of young adults who say they would help with buying a house or renting an apartment and p2 be the proportion of young adults who think that their parents would help USE SALT State the appropriate null and alternative hypotheses Ho P P 0 Ha P P 0 O Ho P P 0 Ha P P 0 Ho P P 0 Ha P P 0 Ho P P 0 Ha P P 0 Ho P P 0 Ha P P 0 Find the test statistic and P value Use a table or SALT Round your test statistic to two decimal places and your P value to four decimal places Project foru 1 pptx TO omparecont RP1 pdf Biki Bike Pr Forum 1 m Project C p Screens 023 0 4 Screen 023 0 C

Suppose that in studies of mobile phone use while driving conducted in 2015 and 2020 3 2 of the drivers observed in 2015 and 2 6 of the drivers observed in 2020 were using a handheld mobile phone while driving Suppose that these percentages were based on observations from independent random samples of 1 500 drivers in 2015 and 1 500 drivers in 2020 USE SALT a Are the sample sizes large enough to use the large sample confidence interval for a difference in population proportions O Yes No b Assume that it is reasonable to regard these samples as representative of drivers in 2015 and drivers in 2020 Estimate the difference in the proportion of drivers in 2015 and the proportion of drivers in 2020 who use a mobile phone while driving using a 95 confidence interval Use 2015 Drivers 2020 Drivers Enter your answer using interval notation Round your numerical values to four decimal places Is 0 included in the confidence interval Yes No What door this suggest about the difference in proportions for 2015 and 2020 Pro omp R Biki Fort L Proje E Se 023

KSTAT3 11 1 010 S USE SALT Many people believe that they experience information overload in today s digital world A report describes a survey in which people were asked if they feel overloaded by information Suppose in a representative sample of 634 college graduates 101 indicated that they suffered from information overload while 118 people in an independent representative sample of 496 people who had never attended college said that they suffered from information overload MY NOTES a Construct a 95 large sample confidence interval for the proportion of college graduates who experience information overload Hint This is a one sample confidence interval Enter your answer using interval notation Round your numerical values to four decimal places Interpret the interval There is a 95 chance that the true proportion of college graduates who experience information overload falls directly in the middle of this interval We are 95 confident that the true difference in the proportion of college graduates who experience information overload and this proportion for people who have never attended college falls within this interval O There is a 95 chance that the true difference in the proportion of college graduates who experience information overload and this proportion for people who have never attended college falls directly in the middle of this interval O We are 95 confident that the true proportion of college graduates who experience information overload falls within this interval We are 95 confident that the true proportion of people who have never attended college who experience information overload falls within this interval b Construct a 95 large sample confidence interval for the proportion of people who have never attended college who experience information overload Enter your answer using interval notation Round your numerical values to four decimal places Interpret the interval Thin05 chance that the true proportion of college graduates who experience information overload falls directly in the middle of this interval for people who have tegreewa BAI Project 1 pp ompare RP1 Biki Bi Forum Projec So 023 S 023

Solve for y y YA Y A 4 V 192 13 192 13 12 13

Solve for b 136 169 Ob 13 Ob 13 13

The gross daily sales at a certain restaurant are a normal random variable with mean 2200 and standard deviation 210 What is the probability that a the total gross sales over the next 2 days exceeds 4840 b daily sales exceed 2100 in at least 2 of the next 3 days What independence assumptions have you made Click the icon to view the standard normal distribution table a The probability that the total gross sales over the next 2 days exceeds 4840 is Round to four decimal places as needed

What changes the width of a confidence interval A marketing director wants a 95 confidence interval for the mean cost of running shoes She randomly samples 40 pairs of shoes and finds that the sample mean was 122 with a samp standard deviation s of 27 The marketing director concluded with 95 confidence that between 113 36 and 130 64 contains the mean cost of all running shoes What would change for a narrower confidence interval Select all answers that will make the width narrower If the sample size increased to 50 pairs of shoes If she increased the confidence level to a 99 confidence level If the sample size decreased to 30 pairs of shoes If the sample standard deviation was smaller If the point estimate was smaller If the sample standard deviation was larger If she decreased the confidence level to a 90 confidence interval If the point estimate was larger

A student was asked to find a 98 confidence interval for widget width using data from a random sample of size n 23 Which of the following is a correct interpretation of the interval 12 9 31 7 Check all that are correct With 98 confidence the mean width of a randomly selected widget will be between 12 9 and 31 7 There is a 98 chance that the mean of the population is between 12 9 and 31 7 There is a 98 chance that the mean of a sample of 23 widgets will be between 12 9 and 31 7 The mean width of all widgets is between 12 9 and 31 7 98 of the time We know this is true because the mean of our sample is between 12 9 and 31 7 With 98 confidence the mean width of all widgets is between 12 9 and 31 7