Statistics Questions

quadratic regression using a graphing calculator to determine a quadratic function that could be used to model the data in the table below Horizontal Distance ft Reflect in ePortfolio 0 10 20 30 40 50 Height ft 5 8 12 20 15 10

humane society claims that less than 70 of households in a certain country own a pet In a random sample of 600 households in that country 396 say they own a pet At a 0 05 is there enough evidence to support the society s aim Complete parts a through c below a Identify the claim and state Ho and H dently the claim in this scenario Select the correct choice below and fill in the answer box to complete your choice Type an integer or a decimal Do not round OA of households in the country own a pet OB The percentage households in the country that own a pet is not OC More than of households in the country own a pet D Less than 70 of households in the country own a pet Let p be the population proportion of successes where a success is a household in the country that owns a pet State Ho and H Select the correct choice below and fill in the answer boxes to complete your choice Round to two decimal places as needed OA H ips Happ OD Ho P H pa b Use technology to find the P value identify the standardized test statistic Round to two decimal places as needed Com OB H p H pz OE Hops H p c H pz 0 70 H p 0 70 OF Ho P H ps

A humane society claims that less than 72 of households in a certain country own a pet In a random sample of 700 households in that country 483 say they own a pet At a 0 05 is there enough evidence to support the society s claim Complete parts a through c below Identify the claim in this scenario Select the correct choice below and fill in the answer box to complete your choice Type an integer or a decimal Do not round OA More than of households in the country own a pet OB The percentage households in the country that own a pet is not C Less than 72 of households in the country own a pet OD of households in the country own a pet Let p be the population proportion of successes where a success is a household in the country that owns a pet State Ho a H Select the correct choice below and fill in the answer boxes to complete your choice Round to two decimal places as needed OA Ho P Ha p O D Ho p Ha ps b Use technology to find the P value Identify the standardized test statistic Z Round to two decimal places as needed OB Ho P H pz E Ho ps Ha p C Ho p 0 72 Ha p 0 72 OF Ho P Ha p

A research center claims that 29 of adults in a certain country would travel into space on a commercial flight if they could afford it In a random sample of 1200 adults in that country 32 say that they would travel into space on a commercial flight they could afford it At a 0 01 is there enough evidence to reject the research center s claim Complete parts a through c below A 29 of adults in the country would travel into space on a commercial flight if they could afford it OB At least of adults in the country would travel into space on a commercial flight if they could afford it OC No more than of adults in the country would travel into space on a commercial flight if they could afford it OD The percentage adults in the country who would travel into space on a commercial flight if they could afford it is not Let p be the population proportion of successes where a success is an adult in the country who would travel into space on a commercial flight if they could afford it State Ho and H Select the correct choice below and fill in the answer boxes to complete your choice Round to two decimal places as needed OA Ho p2 H p OD Ho P H p b Use technology to find the P value Identify the standardized test statistic Z Round to two decimal places as needed OB Ho ps Ha p E Ho p Ha ps OC Ho P H p F Ho p 0 29 H P 0 29

The mean incubation time for a type of fertilized egg kept at a certain temperature is 23 days Suppose that the incubation times are approximately normally distributed with a standard deviation of 2 days Complete parts a through e below Click here to view the standard normal distribution table page 1 Click here to view the standard normal distribution table page 2 c Find and interpret the probability that a randomly selected fertilized egg takes over 27 days to hatch The probability that a randomly selected fertilized egg takes over 27 days to hatch is 0 0228 Round to four decimal places as needed Interpret this probability Select the correct choice below and fill in the answer box to complete your choice A The average proportion of the way to hatching of all eggs fertilized more than 27 days ago is Round to two decimal places as needed B If 100 fertilized eggs were randomly selected 2 of them would be expected to take more than 27 days to hatch Round to the nearest integer as needed OC In every group of 100 fertilized eggs eggs will hatch in more than 27 days Round to the nearest integer as needed d Find and interpret the probability that a randomly selected fertilized egg hatches between 21 and 23 days The probability that a randomly selected fertilized egg hatches between 21 and 23 days is Round to four decimal places as needed

A study found that the mean amount of time cars spent in drive throughs of a certain fast food restaurant was 136 7 seconds Assuming drive through times are normally distributed with a standard deviation of 33 seconds complete parts a through d below Click here to view the standard normal distribution table page 1 Click here to view the standard normal distribution table page 2 CITE The probability that a randomly selected car will get through the restaurant s drive through in less than 75 seconds is 0 0308 Round to four decimal places as needed b What is the probability that a randomly selected car will spend more than 179 seconds in the restaurant s drive through The probability that a randomly selected car will spend more than 179 seconds in the restaurant s drive through is 0 1003 Round to four decimal places as needed c What proportion of cars spend between 2 and 3 minutes in the restaurant s drive through The proportion of cars that spend between 2 and 3 minutes in the restaurant s drive through is 0 5999 Round to four decimal places as needed d Would it be unusual for a car to spend more than 3 minutes in the restaurant s drive through Why The probability that a car spends more than 3 minutes in the restaurant s drive through is so it unusual since the probability is than 0 05 Round to four decimal places as needed be

he mean incubation time for a type of fertilized egg kept at a certain temperature is 23 days Suppose that the cubation times are approximately normally distributed with a standard deviation of 2 days Complete parts a through below lick here to view the standard normal distribution table page 1 lick here to view the standard normal distribution table page 2 Round to the nearest integer as needed OC The average proportion of the way to hatching of all eggs fertilized in the past 19 days is Round to two decimal places as needed Find and interpret the probability that a randomly selected fertilized egg takes over 27 days to hatch he probability that a randomly selected fertilized egg takes over 27 days to hatch is 0 0228 Round to four decimal places as needed terpret this probability Select the correct choice below and fill in the answer box to complete your choice A The average proportion of the way to hatching of all eggs fertilized more than 27 days ago is Round to two decimal places as needed OB If 100 fertilized eggs were randomly selected hatch Round to the nearest integer as needed OC In every group of 100 fertilized eggs Round to the nearest integer as needed of them would be expected to take more than 27 days to eggs will hatch in more than 27 days

Find the indicated probability Round to the nearest thousandth 16 A sample of 4 different calculators is randomly selected from a group containing 18 that are defective and 40 that ha no defects What is the probability that at least one of the calculators is defective 16

A politician claims that the mean salary for managers in his state is more than the national mean 80 000 Assume the the population is normally distributed and the population standard deviation is 9200 The salaries in dollars for a random sample of 30 managers in the state are listed At 0 03 is there enough evidence to support the claim Use technology 77 676 71 220 92 240 77 134 83 958 92 327 OD Ho 80 000 H 80 000 74 863 72 291 78 950 a Identify the null hypothesis and alternative hypothesis OA Ho 280 000 H 80 000 Z b Identify the standardized test statistic 92 973 70 053 96 961 72 673 75 969 77 703 OB Ho 80 000 H 80 000 E Ho 80 000 Ha 80 000 76 249 84 275 86 053 89 501 95 631 70 670 79 330 97 368 96 758 95 357 73 233 72 501 C Ho 80 000 Ha 80 000 F Ho 80 000 Ha 80 000 Round the final answer to two places as needed Round all intermediate values to three places as needed 91 154 78 968 93 241

18 18 A state lottery involves the random selection of six different numbers between 1 and 31 If you select one six number combination what is the probability that it will be the winning combination

A machine that produces a special type of transistor a component of computers has a 2 defective rate The production is considered a random process where each transistor is independent of the others a What is the probability that the 10th transistor produced is the first with a defect Round your answer to four decimal places 01667 b What is the probability that the machine produces no defective transistors in a batch of 100 Round your answer to four decimal places 1326 c On average how many transistors would you expect to be produced before the first with a defect Enter your answer as a whole number 50 What is the standard deviation Round your answer to two decimal places x d Another machine that also produces transistors has a 5 defective rate where each transistor is produced independent of the others On average how many transistors would you expect to be produced with this machine before the first with a defect Enter your answer as a whole number What is the standard deviation Round your answer to two decimal places e Based on your answers to parts c and d how does increasing the probability of an event affect the mean and standard deviation of the wait time until success and the standard deviation decreases decreases V

Find the indicated probability Express your answer as a simplified fraction unless otherwise noted 15 The following table contains data from a study of two airlines which fly to Small Town USA 3 Podunk Airlines Upstate Airlines Number of flights Number of flights which were on time which were late 33 43 6 5

B Points Monday through Thursday when there isn t a holiday the average number of vehicles that visit a particular retailer between 2pm and 3pm each afternoon is 6 4 and y given day follows a Poisson distribution What is the probability that exactly 7 cars will show up next Monday between 2pm and 3pm Round your answer to four decimal places What is the probability that 0 1 or 2 cars will show up next Monday between 2pm and 3pm Round your answer to four decimal places There is an average of 14 7 people who visit during those same hours from vehicles Is it likely that the number of people visiting by car during this hour is also Poisson Explain O The arrivals of individual people would not be independent and so the number of people visiting by car during the hour would not be Poisson O It doesn t matter whether the arrivals of individual people are independent so the number of people visiting by car during the hour would not be Poisson O The arrivals of individual people would be independent and so the number of people visiting by car during the hour would be Poisson O The arrivals of individual people would be independent and so the number of people visiting by car during the hour would not be Poisson The arrivals of individual people would not be independent and so the number of people visiting by car during the hour would be Poisson

Suppose that about 73 of 18 20 year olds consumed alcoholic beverages in any given year We now consider a random sample of eighty 18 20 year olds a How many people would you expect to have consumed alcoholic beverages What is the standard deviation Round your answer to two decimal places b Would you be surprised if there were 70 or more people who have consumed alcoholic beverages Round your answer to two decimal places Since z c What is the probability that 70 or more people in this sample have consumed alcoholic beverages Round your answer to four decimal places which is Select 2 standard deviations away from the mean it Select suprising for there to be 70 or more people who have consumed alcoholic beverages How does this probability relate to your answer to part b In part b we determined it Select be unusual to observe 70 or more people who have consumed an alcoholic beverage based on the z score In part c we found the probability of observing this Colont implying the event Select be unsual Thus the results Select consistent

Do a majority of U S adults believe raising the minimum wage will help the economy or is there a majority who do not believe this A survey of 1 000 U S adults found that 39 believe it will help the economy Conduct an appropriate hypothesis test to help answer the research question Use a significance level of 0 05 State the null and alternative hypotheses Enter for as needed Ho p 50 HA P 50 Determine the test statistic Round your answer to two decimal places Determine the p value Round your answer to four decimal places p value Enter an exact number What is your conclusion O Reject Ho There is insufficient evidence to conclude either a majority of U S adults believe raising the minimum wage will help the economy or a majority don t believe this O Reject Ho There is sufficient evidence to conclude either a majority of U S adults believe raising the minimum wage will help the economy or a majority don t believe this O Fail to reject Ho There is insufficient evidence to conclude either a majority of U S adults believe raising the minimum wage will help the economy or a majority don t believe this 2 O Fail to reject Ho There is sufficient evidence to conclude either a majority of U S adults believe raising the minimum wage will help the economy or a majority don t believe this I need to use the appropriate appendix table or technology to answer this question

10 The table below describes the smoking habits of a group of asthma sufferers Men Women Nonsmoker 433 408 Occasional Regular smoker smoker 66 70 50 31 2 Heavy smoker Total 34 35 583 514

11 A bag contains 6 red marbles 3 blue marbles and 1 green marble Find P not blue

A IRS auditor randomly selects 3 tax returns from 45 returns of which 15 contain errors What is the probability that she elects none of those containing errors Round to four decimal places 9

From the information provided create the sample space of possible outcomes Flip a coin three times

The mean gas mileage for a hybrid car is 57 miles per gallon Suppose that the gasoline mileage is approximately normally distributed with a standard deviation of 3 5 miles per gallon a What proportion of hybrids gets over 60 miles per gallon b What proportion of hybrids gets 51 miles per gallon or less c What proportion of hybrids gets betwee 57 and 61 miles per gallon d What is the probability that a randomly selected hybrid gets less than 45 miles per gallon Click the icon to view a table of areas under the normal curve a The proportion of hybrids that gets over 60 miles per gallon is Round to four decimal places as needed

The mean incubation time of fertilized eggs is 22 days Suppose the incubation times are approximately normally distributed with a standard deviation of 1 day a Determine the 19th percentile for incubation times b Determine the incubation times that make up the middle 39 Click the icon to view a table of areas under the normal curve a The 19th percentile for incubation times is days Round to the nearest whole number as needed

In horse racing a trifecta is a bet that the first three finishers in a race are selected and they are selected in the correct order Does a trifecta involve combinations or permutations Explain Choose the correct answer below O A Because the order of the first three finishers does make a difference the trifecta involves permutations O B Because the order of the first three finishers does make a difference the trifecta involves combinations OC Because the order of the first three finishers does not make a difference the trifecta involves permutations O D Because the order of the first three finishers does not make a difference the trifecta involves combinations

In a certain instant lottery game the chances of a win are stated as 6 in 25 Express the indicated degree of likelihood as a probability value between 0 and 1 inclusive The probability is Round to three decimal places as needed GILD

How could you use a random digit generator or random number table to simulate rain if you knew that 50 of the time with conditions as you have today it will rain CITR Choose the correct answer below OA A random digit generator or random number table cannot be used to simulate rain OB Let the digit 5 represent rain and let any other digit represent no rain Generate random digits and record the results OC Let the digits 1 2 3 4 and 5 represent rain and let the digits 6 7 8 9 and 10 represent no rain Generate random digits and record the results OD Let the digits 0 1 2 3 and 4 represent rain and let the digits 5 6 7 8 and 9 represent no rain Generate random digits and record the results

A student wants to simulate 28 birthdays but she does not have a calculator or software program available so she makes up 28 numbers between 1 and 365 Is it okay to conduct the simulation this way Why or why not Choose the correct answer below CIT O A No People generally favor some numbers over others so that they don t select numbers with a process that is truly random OB No Simulations must be performed with either a calculator or a statistical program OC Yes People are capable of randomly making up numbers between two values OD Yes People are better at picking birth dates than computers since they can base the numbers on the birth dates of people they know

In a certain study the chances of movies with a female lead role are stated as 28 out of 100 Express the indicated degree of likelihood as a probability value between 0 and 1 inclusive The probability is Round to two decimal places as needed

A random sample of 81 eighth grade students scores on a national mathematics assessment test has a mean score of 279 This test result prompts a state school administrator to declare that the mean score for the state s eighth graders on this exam is more than 270 Assume that the population standard deviation is 39 At 0 05 is there enough evidence to support the administrator s claim Complete parts a through e a Write the claim mathematically and identify Ho and H Choose the correct answer below OA Ho 2270 claim H 270 O D Ho 270 claim Ha 270 b Find the standardized test statistic z Z Round to two decimal places as needed B Ho 270 Ha 270 claim E Ho 270 Ha 270 claim CLOS C Ho 270 Ha 270 claim OF Ho 270 claim Ha 270

Suppose the monthly charges for cell phone plans are normally distributed with mean 68 and standard deviation o 19 a Draw a normal curve with the parameters labeled b Shade the region that represents the proportion of plans that charge less than 49 c Suppose the area under the normal curve to the left of X 49 is 0 1587 Provide an interpretation of this result b Choose the correct graph below I 49 68 87 OB 49 68 87 106 O C 49 30 68 106 c Select the correct choice below and fill in the answer box to complete your choice Type a whole number O D 30 49 OA The probability is 0 1587 that a randomly selected cell phone plan in this population is less than month OB The probability is 0 1587 that a randomly selected cell phone plan in this population is more than month T 68 per per

Suppose the birth weights of full term babies are normally distributed with mean 3450 grams and standard deviation o 505 grams Complete parts a through c below b Shade the region that represents the proportion of full term babies who weigh more than 4460 grams Choose the correct graph below A 2945 3450 3955 4460 OB 2440 3450 4460 XC 2440 2945 3450 O D 3450 3955 4460 c Suppose the area under the normal curve to the right of X 4460 is 0 0228 Provide an interpretation of this result Select the correct choice below and fill in the answer box to complete your choice Type a whole number OA The probability is 0 0228 that the birth weight of a randomly chosen full term baby in this population is less than grams OB The probability is 0 0228 that the birth weight of a randomly chosen full term baby in this population is more than grams

Determine whether the following graph can represent a normal density function Could the graph represent a normal density function

Determine if the following statement is true or false The normal curve is symmetric about its mean Choose the best answer below OA The statement is true The mean is the balancing point for the graph of a distribution and therefore all distributions are symmetric about the mean OB The statement is false The normal curve is not symmetric about its mean because the mean is the ba point of the graph of the distribution The median is the point where 50 of the area under the distribut the left and 50 to the right Therefore the normal curve could only be symmetric about its median no its mean OC The statement is true The normal curve is a symmetric distribution with one peak which means the m median and mode are all equal Therefore the normal curve is symmetric about the mean O D The statement is false The mean is the balancing point for the graph of a distribution and therefore it impossible for any distribution to be symmetric about the mean

a What happens to the graph of the normal curve as the mean increases b What happens to the graph of the normal curve as the standard deviation decreases This is a reading assessment question Be certain of your answer because you only get one attempt on this question a Choose the correct answer below A The graph of the normal curve slides right OB The graph of the normal curve compresses and becomes steeper OC The graph of the normal curve flattens out and becomes wider OD The graph of the normal curve slides left OE Nothing happens to the graph of the normal curve

Draw a normal curve with 66 and o 20 Label the mean and the inflection points Choose the correct graph of the normal curve below OA OB 1 66 86 106 Q 26 46 66 Q K OC 46 66 86

The relative frequency histogram represents the length of phone calls on George s cell phone during the month of September Determine whether or not the histogram indicates that a normal distribution could be used as a model for the variable Can a normal distribution be used as a model for the variable O A Yes because the histogram is not symmetric about its mean OB No because the histogram has the shape of a normal curve OC No because the histogram does not have the shape of a normal curve OD Yes because the histogram does not have the shape of a normal curve OE Yes because the histogram has the shape of a normal curve Relative Frequency 0 4 0 2 0 6 Length minutes 12

A study was conducted that resulted in the following relative frequency histogram Determine whether or not the histogram indicates that a normal 0 4T distribution could be used as a model for the variable 0 2 1000 2000 3000 4000 50 Choose the correct answer below OA The histogram is not bell shaped so a normal distribution could not be used as a model for the variable OB The histogram is not bell shaped so a normal distribution could be used as a model for the variable OC The histogram is bell shaped so a normal distribution could not be used as a model for the variable

A dreidel is a four sided spinning top with the Hebrew letters nun gimel hei and shin one on each side Each side is equally likely to come up in a single spin of the dreidel Suppose you spin a dreidel fi times Calculate the probability of getting the following Round your answers to four decimal places a at least one nun b exactly 2 nuns c exactly 1 hei d at most 4 gimels 4

possible for their children to have brown eyes probability 0 75 blue eyes 0 125 or green eyes 0 125 a What is the probability the rst blue eyed child they have is their third child Assume that the eye colors of the children are independent of each other b If they have six children what is the probability that exactly two will have green eyes c If they have six children what is the probability that at least one will have green eyes

me the point estimate of the population proportion the margin of error for the fo ce interval and the number of individuals in the sample with the specified cha sample size provided er bound 0 171 upper bound 0 509 n 1200 nt estimate of the population proportion is to the nearest thousandth as needed

In your reference for this assignment be sure to include both your text class materials AND your outside reading s Initial Post Instructions 1 Present two different types of data or variables used in the health field Examples could be blood pressure temperature pH pain rating scales pulse oximetry hematocrit minute respiration gender age ethnicity etc 2 Classify each of your variables as qualitative or quantitative and explain why they fall into the category that you chose 3 Also classify each of the variables as to their level of measurement nominal ordinal interval or ratio and justify your classifications 4 Which type of sampling could you use to gather your data stratified cluster systematic and convenience sampling Follow Up Post Instructions

Aubrey buys a bag of cookies that contains 7 chocolate chip cookies 9 peanut butter cookies 5 sugar cookies and 8 oatmeal raisin cookies What is the probability that Aubrey randomly selects a peanut butter cookie from the bag eats it then randomly selects another peanut butter cookie Express your answer as a reduced fraction

A very skilled court stenographer makes one typographical error typo per hour on average a What probability distribution is most appropriate for calculating the probability of a given number of typos this stenographer makes in an hour O Poisson O binomial O negative binomial geometric b What are the mean and the standard deviation of the number of typos this stenographer makes Enter your answers as whole numbers 1 1 mean standard deviation c Would it be considered unusual if this stenographer made 5 typos in a given hour Making 5 typos in a given hour is more than two standard deviations above the mean so it would T be unusual d Calculate the probability that this stenographer makes at most 5 typos in a given hour Round your answer to four decimal places

A nonprofit wants to understand the fraction of households that have elevated levels of lead in their drinking water They expect at least 5 of homes will have elevated levels of lead but not more than about 30 They randomly sample 880 homes and work with the owners to retrieve water samples and they compute the fraction of these homes with elevated lead levels They repeat this 1 000 times and build a distribution of sample proportions a What is this distribution called Osampling distribution O geometric distribution O normal distribution O Poisson distribution O binomial distribution b Would you expect the shape of this distribution to be symmetric right skewed or left skewed Explain your reasoning We know the smallest possible value of np is 44 and the smallest possible value of n 1 p is X so the success failure condition is satisfied and we

WorkoutHours TVHours StressLevel Pearson Correlation Sig 2 tailed N Pearson Correlation Sig 2 tailed N Pearson Correlation Sig 2 tailed N 1 40 233 149 40 428 006 40 233 149 40 1 40 053 745 40 428 006 40 053 745 40 1 40 Correlation is significant at the 0 01 level 2 tailed 10 Based on the above Correlation table which correlations are significant

Model R Square 1 431a 186 a Predictors Constant TVHours WorkoutHours Model 1 R Constant WorkoutHours TVHours Square a Dependent Variable StressLevel 142 Unstandardized Coefficients B Std Error 2 669 093 024 Estimate Coefficients 599 032 074 743 Standardized Coefficients Beta 3 440 049 t b Which is the best predictor of StressLevel in this model 4 458 2 883 322 11 Based on the above Regression output please tell me the following a What is the variance accounted for in StressLevel in this model Sig 0

work as follows Tests Quizzes Problem Solving Summative Activity Final Exam Below are the marks that Christie received in each category Problem Category Solving 140 27 Christie s Mark 1 decimal place Category Weighting 68 74 10 Tests 190 141 40 40 15 10 15 20 Tests Quizzes Problem Solving Summative Activity Final Exam Quizzes 100 74 Tests 190 15 40 15 10 15 20 10 Summative Activity 140 30 Question 4 1 point What is Christies on the Summative Activity To calculate the final mark for her math class Mrs Greenfield weights the course work as follows Below are the marks that Christie received in each category Category Quizzes 100 15 Exam 196 78 Problem Summative Solving 140 Activity 140 20 Exam 196

4 Your statistics instructor claims that 60 percent of the students who take her Elementary Statistics class go through life feeling more enriched For some reason that she can t quite figure out most people don t believe her You decide to check this out on your own You randomly survey 64 of her past Elementary Statistics students and find that 34 feel more enriched as a result of her class Using the a 0 05 level of significance is there reason to conclude that the teacher has overestimated and the value is less than 60 State the hypotheses Name the test you will perform Draw and label a bell curve Give the test statistic and p value Give your decision the reason for that decision and your conclusion

8 Why do we care about the variance accounted for r squared in a regression model

6 Dr Hafen is doing research on the effects of study time how many minutes students study on test performance their score on an exam He hypothesizes that the amount of study time will impact an individual s performance on the exam Then Dr Hafen collects data on 100 students and runs a Pearson correlation a In your own words please describe Dr Hafen s Null Hypothesis b If Dr Hafen makes a Type I error what would that mean in the context of the study c If Dr Hafen makes a Type II error what would that mean in the context of the study

2 Previously an organization reported that teenagers spent 4 5 hours per week on average on the phone The organization thinks that currently the mean is higher Fifteen randomly chosen teenagers were asked how many hours per week they spend on the phone The sample mean was 4 75 hours with a sample standard deviation of 2 0 Give the null and alternative hypotheses Do not run a test

7 Why are both sample size N and effect size e g r important when conducting a hypothesis test