Statistics Questions

we do not reject Ho A corresponding relationship between confidence intervals and two talled hypothesis tests also is valid for other parameters such as p or P P which we will study in later sections Whenever the value of k given in the null hypothesis fails outside the c 1 a confidence interval for the parameter we reject Ho For example consider a two talled hypothesis test with a 0 05 and Ho 21 H 21 A random sample of size 30 has a sample mean x 22 from a population with standard deviation 6 a What is the value of c 1 a 0 95 Using the methods of Chapter 7 construct a 1 a confidence interval for from the sample data Round your answers to two decimal places lower limit 19 11 upper limit 24 89 X X H What is the value of u given in the null hypothesis i e what is k k 21 Is this value in the confidence interval Yes O NO Do we reject or fail to reject H based on this information Fall to reject since 21 is not contained in this interval Fail to reject since 21 is contained in this interval Reject since 21 is not contained in this interval Reject since 21 is contained in this interval X b Using methods of Chapter 8 find the P value for the hypothesis test Round your answer to four decimal places 976

Paired differences 10 1 a Two math facts drills were given to 10 students The first was given before PE class and the second was given after PE class The drills were 10 problems of adding two digit integers The following ordered pairs were obtained from the number of correct answers on the first and second drill 8 9 7 9 5 6 6 6 7 6 8 9 10 10 5 7 8 10 9 9 Is there a difference between the scores Test this claim with a 5 level of significance Use z value test b A knitter of fine socks kept track of the number of socks she created in the morning and in the afternoon Each knitting session was 90 minutes long She worked and kept track for one week with the following results for morning then afternoon productivity 4 5 5 3 4 6 4 3 5 5 3 5 5 6 Test the claim that she is more productive in the afternoon using a significance level of 1 Use p value test c Two friends played golf regularly They both made bad shots periodically and this caused them to use colorful language They decided that each time they swore they would pay a fine of 1 Ace and Beau kept track of their outbursts for 8 rounds of golf Their results are shown in the following ordered pairs of Ace Beau 8 5 9 12 5 6 12 7 9 8 15 12 9 12 10 8 Test the

stimating proportions and finding a value for sample size 8 3 a A random survey of customers of McDonald s restaurants was taken The results showed that 18 of the 72 surveyed had once worked at a McDonald s Find a 95 confidence interval for the proportion of McDonald s customers that are former employees b A random survey of students in statistics classes was taken The results showed that 84 out of 112 had majors in the STEM fields Find a 99 confidence interval for the proportion of students in statistics classes with majors in the STEM fields c A random sample of snack size bags of Fritos was taken The results showed that 12 out of 84 bags contained more than the weight shown on the snack size bags of Fritos Find a 90 confidence interval for the proportion of snack size bags of Fritos that contain more than the weight shown on the bag

Find mean standard deviation and z values 7 2 a From 2012 thru 2022 the weight of babies born in hospitals in Metropolis have a normal distribution of with a mean of 7 2 pounds and a standard deviation of 1 pound Create a graph of the distribution with an underlying standard normal distribution shown Illustrate the intervals for x 9 2 and z 1 5 Find the z value for a baby of 5 9 pounds b Assume that the following distribution is approximately normal A random sample of car values of 50 cars parked in the parking garage at UAH on the first Mondays of each month of Spring 2023 semester yielded these results car values 1 million and car values 50 000 million Find the mean standard deviation and the z value of a 30 000 for a car parked in the UAH garage on a first Monday during Spring 2023 semester c During a CoVid lockdown of a family of 8 the sum of their temperatures on the last day of lockdown was 300 degrees Celsius and the sum of their temperatures squared was 11 300 Find the mean standard deviation and the temperature of a family member on the last day of lockdown with a z score of 2

4 Find the number of samples needed for a given significance level historic p know and desired margin of error Find the number of samples needed for a given significance level historic p unknown and desired margin of error Give those formulas Find the sample size needed for a significance level of 2 given a margin of error is 02 and the historic p value is 6 Find the sample size needed for a confidence level of 99 with a desired margin of error of 02 and NO historic p value Make up values and complete 4 more problems

The demand D for a new rollerball pen is given by D 0 006p3 0 3p 150p where p is the price in dollars a Find the rate of change of quantity with respect to price dD dp b How many units will consumers want to buy when the price is 25 per unit c Find the rate of change at p 25 and interpret this result d Would you expect dD dp to be positive or negative

Fill in the blanks by selecting one option from each menu aby Part 1 3 points aby Part 2 3 points Find the 90 confidence interval for the average number of units that students in their college a Part 3 3 points are enrolled in Assume that the distribution of individual student enrollment units at this college is approximately normal ab Part 4 3 points Part 5 3 points Students in a statistics class are conducting a survey to estimate the mean number of units students at their college are enrolled in The students collect a random sample of 52 students The mean of the sample is 12 6 units The sample has a standard deviation of 1 9 units 1 The t value is 2 The standard error has a value of 15 points 3 The margin of error has a value of 4 Find the 90 confidence interval for the average number of units that students in their college are enrolled in

A statistics class is estimating the mean height of all female students at their college They collect a random sample of 43 female students and measure their heights The mean of the sample is 65 4 inches and the sample standard deviation is 5 4 inches Find the 95 confidence interval for the mean height of all female students in their school Assume that the distribution of individual female heights at this school is approximately normal 1 The t value is Fill in the blanks by selecting one option from each menu aby Part 1 3 points ab Part 2 3 points aby Part 3 3 points ab Part 4 3 points ab Part 5 3 points 15 points 2 The standard error has a value of 3 The margin of error has a value of 4 Find the 95 confidence interval for the mean height of all female students in their school

BFW Publishers A group of researchers is designing an experiment to test whether an herbal supplement will help people lose weight The researchers selected a sample of 500 adults who want to lose weight and over the next four months 250 of them will take the herbal supplement daily whereas the remaining 250 will take a placebo daily At the end of the four months the researchers will compare the weight loss for the two groups Why is it important that the researchers use randomization to assign each of the adults who want to lose weight to a treatment group Select all true statements Randomization prevents the adults who want to lose weight from selecting their own treatment group Randomization prevents the researchers from specifically assigning all adults who exercise regularly to take the herbal supplement daily Randomization ensures each treatment group will be similar in everything except the type of pill taken Randomization eliminates lurking variables from the experiment Randomization ensures that there will be an equal number of adults who want to lose weight in each treatment group

4 Assume each outcome is equally likely in the sample space S provided below Find P AC S 0 1 2 3 4 A 0 1 Answer Previous Answer 0 6 Return to overview

A football coach hears that a new exercise program will increase upper body strength better than lifting weights He is eager to test this new program in the off season with the players on his high school team The coach decides to let his players choose which of the two treatments they will undergo for 3 weeks exercise or weight lifting He will use the number of push ups a player can do at the end of the experiment as the response variable Which principle of experimental design does the coach s plan violate Comparison Random assignment Control None The experiment includes all of the principles of experimental design Replication

Sketch the region corresponding to the statement P Z c 0 25 Shade Left of a value 3 Click and drag the arrows to adjust the values 2 T 1 1 5 0 1 2 3 4

5 Determine the interquartile range from the boxplot below Assume that each quartile represented in the boxplot below in an integer 0 H TTT 10 Answer 15 Previous Answer 8 20 G

a State the random variable rv X the cholesterol level of a randomly selected woman age 45 59 in Ghana Nigeria or Seychelles b Find the probability that a randomly selected woman age 45 59 in Ghana Nigeria or Seychelles has a cholesterol level of 2 7 mmol l or more 0 9918 c Find the probability that a randomly selected woman age 45 59 in Ghana Nigeria or Seychelles has a cholesterol level of 7 6 mmol l or less 0 9938 0 0020 d Find the probability that a randomly selected woman age 45 59 in Ghana Nigeria or Seychelles has a cholesterol level between 2 7 and 7 6 mmol l 0 0001 O X e Find the probability that randomly selected woman age 45 59 in Ghana Nigeria or Seychelles has a cholesterol level that is it least 8 6 mmol l OF X 126 65 f Is a cholesterol level of 8 6 mmol l unusually high for a randomly selected woman age 45 59 in Ghana Nigeria or Seychelles Why or why not yes since the probability is greater than 0 05 g What cholesterol level do 44 of all women age 45 59 in Ghana Nigeria and Seychelles have less than Round your answer to two decimal places in the first box Put the correct units in the second box X mmol l X 8

In the United States males between the ages of 40 and 49 eat on average 103 1 g of fat every day with a standard deviation of 4 32 g Assume that the amount of fat a person eats is normally distributed Round the probabilities to four decimal places It is possible with rounding for a probability to be 0 0000 a State the random variable rv X a randomly selected male in the US between the ages of 40 and 49 b Find the probability that a randomly selected male in the US between the ages of 40 and 49 has a fat consumption of 91 74 g or grams or more 0 9957 c Find the probability that a randomly selected male in the US between the ages of 40 and 49 has a fat consumption of 105 94 g or grams or less 0 7454 d Find the probability that a randomly selected male in the US between the ages of 40 and 49 has a fat consumption between 91 74 and 105 94 g or grams e Find the probability that randomly selected male in the US between the ages of 40 and 49 has a fat consumption that is at least 118 22 g or grams f Is a fat consumption of 118 22 g or grams unusually high for a randomly selected male in the US between the ages of 40 and 49 Why or why not Select an answer g What fat consumption do 68 of all males in the US between the ages of 40 and 49 have less than

2 Chi Square Test for Association 3 An advertising firm wanting to target people with strong desires for success conducted a study to see if such people differed in the types of television shows they watched Randomly selected participants recorded the shows they watched for a week then their desire for success was assessed and finally they were divided into two groups Low Success seekers watched 8 comedies 15 romances 6 documentaries 13 dramas and 3 news shows High Success seekers watched 3 comedies 3 romances 9 documentaries 7 dramas and 8 news shows Using this data answer the following State the populations and hypotheses Create a table for the data using SPSS Conduct a Chi Squared for independence test using the SPSS program and post output file State the results using the proper APA format Is the distribution of the type of shows watched different for participants having high and low desires for success

A dishwasher has a mean lifetime of 12 years with an estimated standard deviation of 1 25 years Assume the lifetime of a dishwasher is normally distributed Round the probabilities to four decimal places It is possible with rounding for a probability to be 0 0000 a State the random variable rv X the lifetime of a randomly selected dishwasher b Find the probability that a randomly selected dishwasher has a lifetime of 12 95 years or more 0 2236 c Find the probability that a randomly selected dishwasher has a lifetime of 15 75 years or less 0 9987 d Find the probability that a randomly selected dishwasher has a lifetime between 12 95 and 15 75 years 0 7751 A e Find the probability that randomly selected dishwasher has a lifetime that is at most 8 875 years f Is a lifetime of 8 875 years unusually low for a randomly selected dishwasher Why or why not Select an answer g What lifetime do 40 of all dishwashers have less than Round your answer to two decimal places in the first box Put the correct units in the second box

The mean starting salary for nurses is 67 694 dollars nationally The stand 10 333 dollars Assume that the starting salary is normally distributed Round the probabilities to four decimal places It is possible with rounding for a probability to be 0 0000 a State the random variable rv X a randomly selected nurse b Find the probability that a randomly selected nurse has a starting salary of 40795 7 dollars or more 0 9953 c Find the probability that a randomly selected nurse has a starting salary of 83830 2 dollars or less 0 9406 d Find the probability that a randomly selected nurse has a starting salary between 40795 7 and 83830 2 dollars 0 0547 e Find the probability that randomly selected nurse has a starting salary that is at most 41861 5 dollars g 0 0062 f is a starting salary of 41861 5 dollars unusually low for a randomly selected nurse Why or why not app Select an answer yes since the probability is less than or equal to 0 05 no since the probability is less than or equal to 0 05 yes since the probability is greater than 0 05 no since the probability is greater than 0 05 an OX

In the United States males between the ages of 40 and 49 eat on average 103 1 g of fat every day with a standard deviation of 4 32 g Assume that the amount of fat a person eats is normally distributed Round the probabilities to four decimal places It is possible with rounding for a probability to be 0 0000 a State the random variable rv X a randomly selected male in the US between the ages of 40 and 49 b Find the probability that a randomly selected male in the US between the ages of 40 and 49 has a fat consumption of 91 74 g or grams or more c Find the probability that a randomly selected male in the US between the ages of 40 and 49 has a fat consumption of 105 94 g or grams or less d Find the probability that a randomly selected male in the US between the ages of 40 and 49 has a fat consumption between 91 74 and 105 94 g or grams e Find the probability that randomly selected male in the US between the ages of 40 and 49 has a fat consumption that is at least 118 22 g or grams f is a fat consumption of 118 22 g or grams unusually high for a randomly selected male in the US between the ages of 40 and 49 Why or why not Select an answer g What fat consumption do 68 of all males in the US between the ages of 40 and 49 have less than Round your answer to two decimal places in the first box

The following table lists the number of years of education past high school and the annual income of six people Determine the linear correlation coefficient for the data and also determine whether we can be 95 or 99 confident that there is significant linear correlation between the two variables Years of Education Past High School Annual Income in thousands of iClick the icon to view the table of critical values for the linear correlation coefficient 1 26 2 29 4 38 4 34 6 42 5 39 D The correlation coefficient between the two variables is r Round to four decimal places as needed Table of critical values n 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 05 950 878 811 754 707 666 632 602 576 553 532 514 497 482 468 456 444 01 999 959 917 875 834 798 765 735 708 684 661 641 623 606 590 575 561

The mean cholesterol level of women age 45 59 in Ghana Nigeria and Seychelles is 5 1 mmol l and the standard deviation is 1 0 mmol l Assume that cholesterol levels are normally distributed Round the probabilities to four decimal places It is possible with rounding for a probability to be 0 0000 a State the random variable rv X a randomly selected woman age 45 59 in Ghana Nigeria or Seychelles b Find the probability that a randomly selected woman age 45 59 in Ghana Nigeria or Seychelles has a cholesterol level of 2 7 mmol l or more 0 9918 c Find the probability that a randomly selected woman age 45 59 in Ghana Nigeria or Seychelles has a cholesterol level of 7 6 mmol l or less 0 3821 d Find the probability that a randomly selected woman age 45 59 in Ghana Nigeria or Seychelles has a cholesterol level between 2 7 and 7 6 mmol l 0 3714 X 0 9998 e Find the probability that randomly selected woman age 45 59 in Ghana Nigeria or Seychelles has a cholesterol level that is at least 8 6 mmol l X Why X f is a cholesterol level of 8 6 mmol l unusually high for a randomly selected woman age 45 59 in Ghana Nigeria or Seychelles

State the decision rule to test the null hypothesis 496 people were asked if they were satisfied with their jobs 39 said they were Alternative Hypothesis is H p 0 26 Confidence level 98 O Reject Null Hypothesis Ho if the test statistic is 2 05 O Reject Null Hypothesis Ho if the test statistic is 2 33 O Reject Null Hypothesis Ho if the test statistic is 2 575 O Reject Null Hypothesis Ho if the test statistic is 2 05

Assume that a hypothesis test of the given claim will be conducted Identify the type I or type II error for the test A researcher claims that the amounts of acetaminophen in a certain brand of cold tablets have a standard deviation different from the 3 3 mg claimed by the manufacturer Identify the type II error for the test O The error of rejecting the claim that the standard deviation is more than 3 3 mg when it really is more than 3 3 mg O The error of rejecting the claim that the standard deviation is 3 3 mg when it really is 3 3 mg O The error of failing to reject the claim that the standard deviation is 3 3 mg when it is actually different from 3 3 mg

Use the P value method to test the given hypothesis In a sample of 162 children selected randomly from one town it is found that 36 of them suffer from asthma At the 0 05 significance level test the claim that the proportion of all children in the town who suffer from asthma is 11 O There is not sufficient evidence to support the claim that the proportion of all children in the town who suffer from asthma is 11 O There is not sufficient evidence to warrant rejection of the claim that the proportion of all children in the town who suffer from asthma is 11 O There is sufficient evidence to support the claim that the proportion of all children in the town who suffer from asthma is 11 O There is sufficient evidence to warrant rejection of the claim that the proportion of all children in the town who suffer from asthma is 11

Identify the null hypothesis Ho and the alternative hypothesis H Use u for a claim about a mean p for a claim about a proportion and o for a claim about variation An entomologist writes an article in a scientific journal which claims that fewer than 8 in ten thousand male fireflies are unable to produce light due to a genetic mutation Use the parameter p the true proportion of fireflies unable to produce light O Ho p 0 0008 H p 0 0008 O Ho p 0 0008 H p 0 0008 O Ho p 0 0008 H p 0 0008 O Ho p 0 0008

Compute the test statistic used to test the null hypothesis Out of 90 observations 50 were successes H p0 59 Confidence level 98 O 1 736 O 0 005 O 1 723 O 1 291

Identify the null hypothesis Ho and the alternative hypothesis H Use for a claim about a mean p for a claim about a proportion and o for a claim about variation A researcher claims that the amounts of acetaminophen in a certain brand of cold tablets have a standard deviation different from the o 3 3 mg claimed by the manufacturer O Ho a 3 3 mg H 0 3 3 mg O Ho o 3 3 mg H 0 3 3 mg O Ho o 3 3 mg H 0 3 3mg O Ho a 3 3 mg H 0 3 3 mg

Formulate the indicated conclusion in nontechnical terms Be sure to address original claim Carter Motor Company claims that its new sedan the Libra will average better than 30 m per gallon in the city Assuming that a hypothesis test of the claim has been conducted ar that the conclusion is to reject the null hypothesis state the conclusion in nontechnical terms O There is sufficient evidence to support the claim that the mean is less than 30 miles per gallon O There is not sufficient evidence to support the claim that the mean is less than 30 miles per gallor O There is not sufficient evidence to support the claim that the mean is greater than 30 miles per gallon There is sufficient evidence to support the claim that the mean is greater than 30 miles per gallon

Find the P value for the indicated hypothesis test An airline claims that the no show rate for passengers booked on its flights is less than 6 Of 380 randomly selected reservations 18 were no shows Find the P value for a test of the airline s claim O 0 1230 O 0 3508 O 0 1492

Suppose you have sample data where 20 and n 25 You want to create a 99 confidence interval for the mean Also the sample standard deviation is 4 a What is the point estimate for the mean 20 b What is the critical value for the confidence interval Round to 4 decimal places c What is the margin of error for the confidence interval Round to 3 decimal places d What is the confidence interval Round to 3 decimal places

Use the display of data to find the mean median mode and midrange Frequency The median of the data is 10 8 CO 4 N 0 Score 10 11 12 13 14 The mean of the data is 12 Round to the nearest tenth as needed Pound to the nearest tonth oded

2 The breaking strength of plastic bags used for packaging produce is normally distributed with a mean of 7 5 pounds per square inch and a standard deviation of 2 8 pounds per square inch What proportion of the bags have a breaking strength of a Less than 3 17 pounds per square inch b At least 5 pounds per square inch c Between 5 and 5 pounds per square inch d 98 of the breaking strengths will be between what two values symmetrically distributed around the mean e Below what value 90 of plastic bags fall f Between what two values 99 of bags fall

4 A game is played where a 4 sided die is rolled and then a spinner with 10 equal sized sections labelled 1 thru 10 is spun The player wins 14 if the sum of the two is a 2 3 or 4 The player wins 28 if the sum of the two is 12 or greater a What is the expected winning for each play b What would be a good price to charge for the game Why

1 A health psychologist was interested in women s workout preferences Of the 56 participants surveyed 22 preferred running 8 preferred swimming 15 preferred cross fit and 11 preferred an exercise class Using this information answer the following State the populations and hypotheses for a Chi squared goodness of fit test Solve for Chi Squared for goodness of fit Conduct chi squared test for goodness of fit using the SPSS program and paste the output file State the answer using proper APA format

Data on Scholastic Aptitude Test SAT scores are published by the College Entrance Examination Board in National College Bound Senior SAT scores for randomly selected students from each of four high school rank categories are displayed in the following table Sample mean Sample Top Tenth 528 586 680 628 Second Second Third Tenth Fifth Fifth 7500 514 649 372 457 506 440 521 718 370 413 321 532 556 495 077 470 424 478 8 518 8 397 330 00107

1 The circus club has 22 members There are 9 jugglers and 13 tumblers The club will select 5 members to perform in the upcoming variety show a What is the probability that 4 jugglers are chosen b What is the expected number of tumblers in a group this size c The group wants to be fair and randomly select members but agrees that the president who is a tumbler should go and at least 2 jugglers What is the probability that this happens Hint You ware more likely to get this question correct if you use direct reasoning 2 The Birket Lottery hopes to sell two million tickets prizes of 50000 and 20 third prizes of 1000 grand prize is four million dollars there will be 5 second a Find the expected winnings for each ticket b How much do you think the Birket Lottery should set the ticket price at Why kot prico

The time it takes me to wash the dishes on a randomly selected night is uniformly distributed between 7 minutes and 19 minutes a State the random variable in the context of this problem Orv X a uniform distribution Orv X washing dishes rv X the time it takes me to wash dishes on a randomly selected night Orv X a randomly selected night b Compute the height of the uniform distribution Leave your answer as a fraction 1 13 c Which of the following is the correct description of the picture of the probability distribution of X X O a bell shaped curve that starts at 7 and ends at 19 a rectangle with edges at 7 and 19 d What is the probability that washing dishes tonight will take me between 8 and 16 minutes Give your answer as a fraction 7 13 X Give your answer accurate to three decimal places

3 It is estimate that 40 of the general population wears glasses If a random group of 15 people are selected what is the probability that a 11 People will wear glasses b Over 11 people will wear glasses C What is the expected number of people wearing glasses in a group this size 4 A game is played where a 4 sided die is rolled and then a spinner with 10 equal sized sections labelled 1 thru 10 is spun The player wins 14 if the sum of the two is a 2 3 or 4 The player wins 28 if the sum of the two is 12 or greater a What is the expected winning for each play h What would be a good price to charge for the game Why

The mean yearly rainfall in Sydney Australia is about 137 mm and the standard deviation is about 69 mm Assume yearly rainfall is normally distributed Round the probabilities to four decimal places It is possible with rounding for a probability to be 0 0000 a State the random variable Select an answer A b Find the probability that a randomly selected year of rain in Sydney Australia has a yearly rainfall of 211 4 mm or more c Find the probability that a randomly selected year of rain in Sydney Australia has a yearly rainfall of 248 4 mm or less d Find the probability that a randomly selected year of rain in Sydney Australia has a yearly rainfall between 211 4 and 248 4 mm e Find the probability that a randomly selected year of rain in Sydney Australia has a yearly rainfall that is at most 33 5 mm f Is a yearly rainfall of 33 5 mm unusually low for a randomly selected year of rain in Sydney Australia Why or why not Select an answer g What yearly rainfall do 44 of all years of rain in Sydney Australia have more than Round your answer to two decimal places in the first box Put the correct units in the second box

The mean starting salary for nurses is 67 694 dollars nationally The standard deviation is approximately 10 333 dollars Assume that the starting salary is normally distributed Round the probabilities to four decimal places It is possible with rounding for a probability to be 0 0000 a State the random variable Select an answer b Find the probability that a randomly selected nurse has a starting salary of 40795 7 dollars or more c Find the probability that a randomly selected nurse has a starting salary of 83830 2 dollars or less d Find the probability that a randomly selected nurse has a starting salary between 40795 7 and 83830 2 dollars e Find the probability that randomly selected nurse has a starting salary that is at most 41861 5 dollars f is a starting salary of 41861 5 dollars unusually low for a randomly selected nurse Why or why not Select an answer g What starting salary do 47 of all nurses have more than Round your answer to two decimal places in the first box Put the correct units in the second box

The size of fish is very important to commercial fishing A study conducted in 2012 found the length of Atlantic cod caught in nets in Karlskrona to have a mean of 49 9 cm and a standard deviation of 3 74 cm Round the probabilities to four decimal places It is possible with rounding for a probability to be 0 0000 a State the random variable Select an answer b Find the probability that a randomly selected Atlantic cod has a length of 52 78 cm or more c Find the probability that a randomly selected Atlantic cod has a length of 57 18 cm or less d Find the probability that a randomly selected Atlantic cod has a length between 52 78 and 57 18 cm e Find the probability that randomly selected Atlantic cod has a length that is at least 62 99 cm f Is a length of 62 99 cm unusually high for a randomly selected Atlantic cod Why or why not Select an answer g What length do 75 of all Atlantic cod have more than Round your answer to two decimal places in the first box Put the correct units in the second box

According to the WHO MONICA Project the mean blood pressure for people in China is 128 mmHg with a standard deviation of 23 mmHg Assume that blood pressure is normally distributed Round the probabilities to four decimal places It is possible with rounding for a probability to be 0 0000 a State the random variable Select an answer b Find the probability that a randomly selected person in China has a blood pressure of 115 9 mmHg or more c Find the probability that a randomly selected person in China has a blood pressure of 168 4 mmHg or less d Find the probability that a randomly selected person in China has a blood pressure between 115 9 and 168 4 mmHg e Find the probability that randomly selected person in China has a blood pressure that is at most 70 5 mmHg f is a blood pressure of 70 5 mmHg unusually low for a randomly selected person in China Why or why not Select an answer g What blood pressure do 71 of all people in China have less than Round your answer to two decimal places in the first box Put the correct units in the second box

The times required by three workers to perform an assembly line task were recorded on five randomly selected occasions Here are the times to the nearest minute Sample mean Sample variance Hank Joe Susan 8 8 10 10 9 9 9 11 8 11 10 9 10 9 6 10 9 8 8 9 8 1 3 0 7 0 7

Four brands of flashlight batteries are to be compared by testing each brand in five flashlights Twenty flashlights are randomly selected and divided randomly into four groups of five flashlights each Then each group of flashlights uses a different brand of battery The lifetimes of the batteries to the nearest hour are as follows Brand Brand Brand Brand A B C D 42 28 24 20 30 36 36 32 39 31 28 38 28 32 28 28 29 27 33 25 Preliminary data analyses indicate that the independent samples come from normal populations with equal standard deviations At the 5 significance level does there appear to be a difference in mean lifetime among the four brands of batteries Type in SSB SSW and F test statistic Type your conclusion in the space below

Engineers must consider the breadths of male heads when designing helmets The company researchers have determined that the population of potential clientele have head breadths that are Normally distributed with a mean of 5 8 inches and a standard deviation of 1 2 inches Using the Empirical Rule what is the approximate percentage of head breadths that are between 2 2 and 3 4 inches Do not enter the percent symbol ans

How fast can male college students run a mile There s lots of variation of course During World War II physical training was required for male students in many colleges as preparation for military service That provided an opportunity to collect data on physical performance on a large scale A study of 12 000 able bodied male students at the University of Illinois found that their times for the mile run were approximately Normal with mean 7 02 minutes and standard deviation 0 7 minute It s good practice to draw a Normal curve on which this mean and standard deviation are correctly located To do this draw an unlabeled Normal curve locate the points where the curvature changes this is 1 standard deviation from the mean then add number labels on the horizontal axis Use the Empirical Rule to answer the following questions a What range of times covers the middle 95 of this distribution minutes Round to 1 decimal place b What percent of these runners run the mile between 6 32 and 8 42 minutes Round to 1 decimal place c What percentage of the these running times are faster than 9 12 minutes Round to 1 decimal place From to

The graph illustrates the Distribution of the Prices of College Textbooks l 140 161 182 203 224 245 266 Distribution of the Prices of College Textbooks 9 What is the mean of this normal distribution What is the standard deviation of this normal distribution

13 11 c Which of the following is the correct picture of the probability distribution of X O a bell shaped curve that starts at 0 and ends at 11 a rectangle with edges at 0 and 11 d What is the probability that a randomly selected commuter on the Red Line during peak rush hours wait between 2 and 5 minutes Give your answer as a fraction 11 X Give your answer accurate to three decimal places 0 181 X e What is the probability that a randomly selected commuter on the Red Line during peak rush hours wa exactly 2 minutes

The time it takes me to wash the dishes on a randomly selected night is uniformly distributed between 7 minutes and 19 minutes a State the random variable in the context of this problem Orv X a uniform distribution Orv X washing dishes Orv X the time it takes me to wash dishes on a randomly selected night Orv X a randomly selected night b Compute the height of the uniform distribution Leave your answer as a fraction c Which of the following is the correct description of the picture of the probability distribution of X O a bell shaped curve that starts at 7 and ends at 19 O a rectangle with edges at 7 and 19 d What is the probability that washing dishes tonight will take me between 8 and 16 minutes Give your answer as a fraction Give your answer accurate to three decimal places

The weights of 9 ounce bags of a particular brand of potato chips can be modeled by a normal distribution with mean u 9 12 ounces and standard deviation o 0 05 ounce Use the empirical rule to answer the following questions a What percent of bags weigh less than 9 07 ounces b What proportion of bags weigh between 8 97 and 9 17 ounces Enter your answer in decimal form Do not round Do not round