Deck 10: T Tests, Two-Way Tables, and Anova

Question 1

Test whether he given claim is supported or not supported using a 0.05 significance level. Assume that the sample has been randomly selected from a population with a normal distribution.

-A trucking firm suspects that the mean life of a certain tire it uses is less than 34,000 miles. To check the claim, the firm randomly selects and tests 18 of these tires and gets a mean lifetime of 33,400 miles with a standard deviation of 1200 miles. Use a 0.05 significance level to test whether the trucking firm's claim is supported or not supported.

A)supported
B)not supported

Answer 1

supported

Question 2

A simple random sample of 30 households was selected from a particular neighborhood. The number of cars for each household is shown below. Construct the 95% confidence interval estimate of the population mean.
$\begin{array} { l l l l l l l l l l } 2 & 0 & 1 & 2 & 3 & 2 & 1 & 0 & 1 & 4 \\ 1 & 3 & 2 & 0 & 1 & 1 & 2 & 3 & 1 & 2 \\ 1 & 0 & 2 & 0 & 3 & 2 & 2 & 1 & 0 & 2 \end{array}$

A) $1.0$ cars $< \mu < 2.0$ cars
B) $1.5$ cars $< \mu < 1.9$ cars
C) $1.3$ cars $< \mu < 1.7$ cars
D) $1.1$ cars $< \mu < 1.9$ cars

Answer 2

$1.1$ cars $< \mu < 1.9$ cars

Question 3

Test whether he given claim is supported or not supported using a 0.05 significance level. Assume that the sample has been randomly selected from a population with a normal distribution.

-A manufacturer makes ball bearings that are supposed to have a mean weight of 30 grams. A retailer suspects that the mean weight is actually less than 30 grams. The mean weight for a random sample of 16 ball bearings is 28.5 grams with a standard deviation of 4 grams. Use a 0.05 significance level to test whether the claim that the mean is less than 30 grams is supported or not supported.

A)supported
B)not supported

Answer 3

not supported

Question 4

Determine the null and alternative hypotheses for the study that produced the data in the table.

-A researcher performed a study to determine whether an association exists between sex and blood type. He obtained the following sample data.

A) $\mathrm { H } _ { 0 }$ : Sex and blood type are independent.
$\mathrm { H } _ { \mathrm { a } }$ : There is some relationship between sex and blood type.

B) $\mathrm { H } _ { 0 }$ : There is some relationship between sex and blood type.
$\mathrm { H } _ { \mathrm { a } }$ : Sex and blood type are not independent.

C) $\mathrm { H } _ { 0 }$ : There is some relationship between sex and blood type.
$\mathrm { H } _ { \mathrm { a } }$ : Sex and blood type are independent.

D) $\mathrm { H } _ { 0 }$ : Sex and blood type are independent.
$\mathrm { H } _ { \mathrm { a } }$ : There is no relationship between sex and blood type.

Question 5

Among a simple random sample of 12 students selected from one college, the mean number of siblings is 1.3 with a standard deviation of 1.1. Construct the 95% confidence interval estimate of the population mean.

A) $1.1 < \mu < 1.5$
B) $0.66 < \mu < 1.9$
C) $10.1 < \mu < 13.9$
D) $1.0 < \mu < 1.6$

Question 6

Assume that the results of a yes/no survey question given to a random sample of male and female subjects are summarized in a 2 × 2 two-way table. Use the given values of the test statistic and the significance level to test for
independence between gender and response.

-Given a test statistic of $\chi ^ { 2 } = 7.7$ and a significance level = 0.01, decide whether gender and response are related
Or not related.

A)related
B)not related

Question 7

Test whether he given claim is supported or not supported using a 0.05 significance level. Assume that the sample has been randomly selected from a population with a normal distribution.

-A fast food outlet claims that the mean waiting time in line is less than 3.7 minutes. A random sample of 20 customers has a mean of 3.5 minutes with a standard deviation of 0.8 minute. Use a significance level of 0.05 to test whether the fast food outlet's claim is supported or not supported.

A)not supported
B)supported

Question 8

Test whether he given claim is supported or not supported using a 0.05 significance level. Assume that the sample has been randomly selected from a population with a normal distribution.

-A researcher wants to check the claim that convicted burglars spend an average of 18.7 months in jail. She takes a random sample of 11 such cases from court files and finds that x = 20.8 months and s = 7.4 months. Use a 0.05
Significance level to test whether the claim that that the average time is not 18.7 months is supported or not
Supported.

A)supported
B)not supported

Question 9

How tall is your average statistics classmate? To determine this, you measure the height of a simple random sample of 38 fellow students, finding a mean height of 68 inches and a standard deviation of 2.3 inches. Construct the 95% confidence interval estimate of the population mean.

A) $68.2$ in. $< \mu < 68.8$ in.
B) $67.2$ in. $< \mu < 68.8$ in.
C) $67.2$ in. $< \mu < 69.8 \mathrm { in }$ .
D) $68.2$ in. $< \mu < 69.8$ in.

Question 10

Test whether he given claim is supported or not supported using a 0.05 significance level. Assume that the sample has been randomly selected from a population with a normal distribution.

-Researchers have claimed that the average number of headaches during a semester of Statistics is 18. Statistics professors dispute this claim vehemently. They believe the average is much higher. They sample 16 students and find the sample mean is 20 and the sample standard deviation is 3.0. Use a 0.05 significance level to test whether the claim that the average number of headaches is greater than 18 is supported or not supported.

A)not supported
B)supported

Question 11

Determine the null and alternative hypotheses for the study that produced the data in the table.

-A car insurance company performed a study to determine whether an association exists between age and the frequency of car accidents. They obtained the following sample data.

A) $\mathrm { H } _ { 0 }$ : Number of accidents in the past three years and age group are independent. $\mathrm { H } _ { \mathrm { a } }$ : Number of accidents in the past three years and age group are not related.
B) $\mathrm { H } _ { 0 }$ : Number of accidents in the past three years and age group are somehow related. $\mathrm { H } _ { \mathrm { a } }$ : Number of accidents in the past three years and age group are not independent.
C) $\mathrm { H } _ { 0 }$ : Number of accidents in the past three years and age group are independent. $\mathrm { H } _ { \mathrm { a } } :$ Number of accidents in the past three years and age group are somehow related.
D) $\mathrm { H } _ { 0 }$ : Number of accidents in the past three years and age group are somehow related. $\mathrm { H } _ { \mathrm { a } }$ : Number of accidents in the past three years and age group are independent.

Question 12

A sociologist develops a test to measure attitudes about public transportation, and a simple random sample of 27 subjects are given the test. Their mean score is 76.2 and their standard deviation is 21.6. Assume that the population of these scores is normally distributed. Construct the 95% confidence interval estimate of the population mean.

A) $64.2 < \mu < 88.2$
B) $69.2 < \mu < 83.2$
C) $67.7 < \mu < 84.7$
D) $74.6 < \mu < 77.8$

Question 13

Assume that the results of a yes/no survey question given to a random sample of male and female subjects are summarized in a 2 × 2 two-way table. Use the given values of the test statistic and the significance level to test for
independence between gender and response.

-Given a test statistic of $\chi ^ { 2 } = 2.6$ and a significance level = 0.05, decide whether gender and response are related
Or not related.

A)not related
B)related

Question 14

Assume that the results of a yes/no survey question given to a random sample of male and female subjects are summarized in a 2 × 2 two-way table. Use the given values of the test statistic and the significance level to test for
independence between gender and response.

-Given a test statistic of $\chi ^ { 2 } = 3.4$ and a significance level = 0.01, decide whether gender and response are related
Or not related.

A)not related
B)related

Question 15

Test whether he given claim is supported or not supported using a 0.05 significance level. Assume that the sample has been randomly selected from a population with a normal distribution.

-A manufacturer claims that the mean lifetime of its fluorescent bulbs is 1300 hours. A product tester selects 25 bulbs and finds the mean lifetime to be 1280 hours with a standard deviation of 80 hours. He claims that the mean lifetime is different from 1300 hours. Use a significance level of 0.05 to test whether the product tester's claim is supported or not supported.

A)supported
B)not supported

Question 16

A laboratory tested a simple random sample of twelve chicken eggs and found that the mean amount of cholesterol was 215 milligrams with s = 19.8 milligrams. Assume that the population of these amounts is normally distributed. Construct the 95% confidence interval estimate of the population mean.

A) $199.5 \mathrm { mg } < \mu < 230.5 \mathrm { mg }$
B) $209.3 \mathrm { mg } < \mu < 220.7 \mathrm { mg }$
C) $204.7 \mathrm { mg } < \mu < 225.3 \mathrm { mg }$
D) $202.4 \mathrm { mg } < \mu < 227.6 \mathrm { mg }$

Question 17

You want to estimate the average gasoline price in your city for a gallon of regular gasoline. You take a simple random sample of prices from 17 gasoline stations, recording an average cost of $2.07 and a standard deviation of $0.06. Assume that the population of these prices is normally distributed. Construct the 95% confidence interval estimate of the population mean. Round your estimates to the nearest cent.

A) $\$ 2.01 < \mu < \$ 2.13$
B) $\$ 2.06 < \mu < \$ 2.08$
C) $\$ 2.04 < \mu < \$ 2.10$
D) $\$ 2.04 < \mu < \$ 2.08$

Question 18

Assume that the results of a yes/no survey question given to a random sample of male and female subjects are summarized in a 2 × 2 two-way table. Use the given values of the test statistic and the significance level to test for
independence between gender and response.

-Given a test statistic of $\chi ^ { 2 } = 4.6$ and a significance level = 0.05, decide whether gender and response are related
Or not related.

A)related
B)not related

Question 19

Determine the null and alternative hypotheses for the study that produced the data in the table.

-A researcher performed a study to determine whether an association exists between political party affiliation and income. She obtained the following sample data.

A) $\mathrm { H } _ { 0 }$ : Income bracket and party affiliation are independent. $\mathrm { H } _ { \mathrm { a } }$ : Income bracket and party affiliation are somehow related.
B) $\mathrm { H } _ { 0 }$ : Income bracket and party affiliation are somehow related. $\mathrm { H } _ { \mathrm { a } }$ : Income bracket and party affiliation are not independent.
C) $\mathrm { H } _ { 0 }$ : Income bracket and party affiliation are independent. $\mathrm { H } _ { \mathrm { a } }$ : Income bracket and party affiliation are not related.
D) $\mathrm { H } _ { 0 }$ : Income bracket and party affiliation are somehow related.
$\mathrm { H } _ { \mathrm { a } }$ : Income bracket and party affiliation are independent.

Question 20

Test whether he given claim is supported or not supported using a 0.05 significance level. Assume that the sample has been randomly selected from a population with a normal distribution.

-In tests of a computer component, it is found that the mean time between failures is 520 hours. A modification is made which is supposed to increase the time between failures. Tests on a random sample of 10 modified components resulted in the following times (in hours)between failures.

$$\begin{array} { l l l l l } 518 & 548 & 561 & 523 & 536 \\499 & 538 & 557 & 528 & 563\end{array}$$
Use a significance level of 0.05 to test whether the claim that the mean time between failures is greater than 520 hours
Is supported or not supported.

A)not supported
B)supported

Question 21

Find the value of the test statistic for a hypothesis test of independence. Round your answer to 3 decimal places.
Below are sample data to test whether car color affects the likelihood of being in an accident.

A)0.429
B)0.807
C)0.924
D)0.599

Question 22

Using a significance level of 0.05, test the claim that the two variables are independent. State whether the variables are related or not related.

-Below are sample data to test whether car color affects the likelihood of being in an accident. $$\begin{array} { l | c c c } & \text { Red } & \text { Blue } & \text { White } \\\hline \text { Car has been in accident } & 28 & 33 & 35 \\\text { Car has not been in accident } & 23 & 22 & 30\end{array}$$

A)not related
B)related

Question 23

Find the value of the $\chi ^ { 2 }$ test statistic for a hypothesis test of independence. Round your answer to 3 decimal places.

-Responses to a survey question are broken down according to gender and the sample results are given below.
$$\begin{array} { l | c c c } & \text { Yes } & \text { No } & \text { Undecided } \\\hline \text { Male } & 25 & 50 & 15 \\\text { Female } & 20 & 30 & 10\end{array}$$

A)0.749
B)0.579
C)0.759
D)0.921

Question 24

Find the value of the $\chi ^ { 2 }$ test statistic for a hypothesis test of independence. Round your answer to 3 decimal places.

-A medical researcher is interested in determining if there is a relationship between adults over 50 who walk regularly and low, moderate, and high blood pressure. A random sample of 236 adults over 50 is selected and the results are given below. $$\begin{array} { l | c c c } \text { Blood Pressure } & \text { Low } & \text { Moderate } & \text { High } \\\hline \text { Walkers } & 35 & 62 & 25 \\\text { Non-walkers } & 21 & 65 & 28\end{array}$$

A)9.210
B)0.176
C)3.473
D)3.743

Question 25

Using a significance level of 0.05, test the claim that the two variables are independent. State whether the variables are related or not related.

-Tests for adverse reactions to a new drug yielded the results given in the table.
$$\begin{array} { l | c c } & \text { Drug } & \text { Placebo } \\\hline \text { Headaches } & 11 & 7 \\\text { No headaches } & 73 & 91\end{array}$$

A)related
B)not related

Question 26

Determine the null and alternative hypotheses for the study that produced the data in the table.

-A researcher performed a study to determine whether an association exists between retirement age and career. she obtained the following sample data.

A) $\mathrm { H } _ { 0 }$ : Age at retirement and career are independent.
$\mathrm { H } _ { \mathrm { a } }$ : There is no relationship between age at retirement and career.
B) $\mathrm { H } _ { 0 }$ : There is some relationship between age at retirement and career.
$\mathrm { H } _ { \mathrm { a } }$ : Age at retirement and career are independent.
C) $\mathrm { H } _ { 0 }$ : Age at retirement and career are independent.
$\mathrm { H } _ { \mathrm { a } }$ : There is some relationship between age at retirement and career.
D) $\mathrm { H } _ { 0 }$ : There is some relationship between age at retirement and career.
$\mathrm { H } _ { \mathrm { a } }$ : Age at retirement and career are not independent.

Question 27

Using a significance level of 0.05, test the claim that the two variables are independent. State whether the variables are related or not related.

-A medical researcher is interested in determining if there is a relationship between adults over 50 who walk regularly and low, moderate, and high blood pressure. A random sample of 236 adults over 50 is selected and the results are given below. $$\begin{array} { l | c c c } \text { Blood Pressure } & \text { Low } & \text { Moderate } & \text { High } \\\hline \text { Walkers } & 50 & 62 & 25 \\\text { Non-walkers } & 21 & 65 & 28\end{array}$$

A)related
B)not related

Question 28

Calculate the indicated expected frequency to the nearest whole number.

-The two-way table summarizes data from a survey at a small liberal arts college:


Assuming that status and gender are independent, what is the expected frequency of tenure track women?

A) 18
B) 19
C) 8
D) 21

Question 29

Using a significance level of 0.05, test the claim that the two variables are independent. State whether the variables are related or not related.

-160 students who were majoring in either math or English were asked a test question, and the researcher recorded whether they answered the question correctly. The sample results are given below. $$\begin{array} { l | c c } & \text { Correct } & \text { Incorrect } \\\hline \text { Math } & 27 & 53 \\\text { English } & 43 & 37\end{array}$$

A)related
B)not related

Question 30

The Book Industry Study Group, Inc., performs sample surveys to obtain information on characteristics of book readers. A book reader is defined to be one who read one or more books in the six months prior to the survey; a non-book reader is defined to be one who read newspapers or magazines but no books in the six months prior to the survey; a nonreader is defined to be one who did not read a book, newspaper, or magazine in the six months prior to the survey. The following data were obtained from a random sample of 1429 persons 16 years old and over

A) $\mathrm{H}_{0}$ : Household income and reading classification are somehow related. $\mathrm{H}_{\mathrm{a}}$ : Household income and reading classification are not independent.

B) $\mathrm{H}_{0}$ : Household income and reading classification are independent. $\mathrm{H}_{\mathrm{a}}$ : Household income and reading classification are somehow related.

C) $\mathrm{H}_{0}$ : Household income and reading classification are independent. $\mathrm{H}_{\mathrm{a}}$ : Household income and reading classification are not related.

D) $\mathrm{H}_{0}$ : Household income and reading classification are somehow related. $\mathrm{H}_{\mathrm{a}}$ : Household income and reading classification are independent.

Question 31

Calculate the indicated expected frequency to the nearest whole number.

-The two-way table summarizes data from a survey at a small liberal arts college:
Assuming that status and gender are independent, what is the expected frequency of adjunct women?

A)6
B)16
C)20
D)17

Question 32

A study was recently done to examine the relationship between car color and the likelihood of being in an accident. The data is given in the table below.
$\begin{array}{c|ccc} & \text { Red } & \text { Blue } & \text { White } \\\hline \text { Car has been in } & & & \\\text { accident } & 28 & 31 & 36 \\\text { Car has not been } & & & \\\text { in accidentt } & 24 & 22 & 30\end{array}$

A) $\mathrm { H } _ { 0 }$ : The likelihood of being in an accident and car color are independent. $\mathrm { H } _ { \mathrm { a } }$ : The likelihood of being in an accident and car color are somehow related.
B) $\mathrm { H } _ { 0 }$ : The likelihood of being in an accident and car color are somehow related. $\mathrm { H } _ { \mathrm { a } }$ : The likelihood of being in an accident and car color are independent.
C) $\mathrm { H } _ { 0 }$ : The likelihood of being in an accident and car color are somehow related. $\mathrm { H } _ { \mathrm { a } }$ : The likelihood of being in an accident and car color are not independent.
D) $\mathrm { H } _ { 0 }$ : The likelihood of being in an accident and car color are independent. $\mathrm { H } _ { \mathrm { a } }$ : The likelihood of being in an accident and car color are not related.

Question 33

Subjects in a test were given a new drug or a placebo, and then their reactions (headache or no headache)were recorded. The results are given in the table below.
$\begin{array}{r|rr} & \text { Drug } & \text { Placebo } \\\hline \text { Headaches } & 19 & 7 \\\text { No headaches } & 73 & 95\end{array}$

A) $\mathrm { H } _ { 0 }$ : The drug and the occurrence of headaches are independent.
$\mathrm { H } _ { \mathrm { a } }$ : There is a relationship between the drug and the occurrence of headaches.
B) $\mathrm { H } _ { 0 }$ : The drug and the occurrence of headaches are independent.
$\mathrm { H } _ { \mathrm { a } }$ : There is no relationship between the drug and the occurrence of headaches.
C) $\mathrm { H } _ { 0 }$ : There is a relationship between the drug and the occurrence of headaches.
$\mathrm { H } _ { \mathrm { a } }$ : The drug and the occurrence of headaches are not independent.
D) $\mathrm { H } _ { 0 }$ : There is a relationship between the drug and the occurrence of headaches.
$\mathrm { H } _ { \mathrm { a } }$ : The drug and the occurrence of headaches are independent.

Question 34

Calculate the indicated expected frequency to the nearest whole number.

-The two-way table summarizes data from a survey at a small liberal arts college:



Assuming that status and gender are independent, what is the expected frequency of adjunct men?

A) 25
B) 18
C) 10
D) 16

Question 35

Find the value of the test statistic for a hypothesis test of independence. Round your answer to 3 decimal places.
Responses to a survey question are broken down according to employment status and the sample results are
Given below.

A)5.991
B)5.492
C)0.051
D)5.942

Question 36

Calculate the indicated expected frequency to the nearest whole number.

-The two-way table summarizes data from a survey at a small liberal arts college:


Assuming that status and gender are independent, what is the expected frequency of tenure track men?

A) 20
B) 18
C) 16
D) 7

Question 37

Find the value of the test statistic for a hypothesis test of independence. Round your answer to 3 decimal places.
Tests for adverse reactions to a new drug yielded the results given in the table.

Question 38

Find the value of the $\chi ^ { 2 }$ test statistic for a hypothesis test of independence. Round your answer to 3 decimal places.

-160 students who were majoring in either math or English were asked a test question, and the researcher recorded whether they answered the question correctly. The sample results are given below. $$\begin{array} { l | c c } & \text { Correct } & \text { Incorrect } \\\hline \text { Math } & 27 & 53 \\\text { English } & 43 & 37\end{array}$$

A)0.011
B)6.205
C)6.635
D)6.502

Question 39

Using a significance level of 0.05, test the claim that the two variables are independent. State whether the variables are related or not related.

-Responses to a survey question are broken down according to gender and the sample results are given below.
$$\begin{array} { l | c c c } & \text { Yes } & \text { No } & \text { Undecided } \\\hline \text { Male } & 25 & 52 & 15 \\\text { Female } & 20 & 30 & 10\end{array}$$

A)not related
B)related

Question 40

Using a significance level of 0.05, test the claim that the two variables are independent. State whether the variables are related or not related.

-Responses to a survey question are broken down according to employment status and the sample results are given below. $$\begin{array} { l | r c c } & \text { Yes } & \text { No } & \text { Undecided } \\\hline \text { Employed } & 30 & 15 & 7 \\\text { Unemployed } & 20 & 25 & 10\end{array}$$

A)not related
B)related

Question 41

Use software to conduct the analysis of variance test. Use a significance level of 0.05 to test the null hypothesis.

-The grade point averages of students participating in sports at a local college are to be compared. The data are listed below. Do the data indicate that there is a difference in mean grade point average for the three groups?
$$\begin{array} { c | c | c } \text { Tennis } & \text { Golf } & \text { Swimming } \\\hline 2.6 & 1.8 & 2.7 \\3.2 & 3.3 & 3.0 \\2.5 & 1.9 & 2.8 \\3.5 & 2.1 & 2.5 \\3.1 & 1.9 & 2.5 \\2.1 & 2.4 & 2.6\end{array}$$

A)Yes
B)No

Question 42

Use software to conduct the analysis of variance test. Use a significance level of 0.05 to test the null hypothesis.

-A medical researcher wishes to try three different techniques to lower blood pressure of patients with high blood pressure. The subjects are randomly selected and assigned to one of three groups. Group 1 is given medication, Group 2 is given an exercise program, and Group 3 is assigned a diet program. At the end of six weeks, each subject's blood pressure is recorded.Do the data indicate that there is a difference in mean blood Pressure for the three groups? $$\begin{array} { c c c } \hline \text { Group 1 } & \text { Group 2 } & \text { Group 3 } \\\hline 9 & 8 & 4 \\12 & 5 & 12 \\11 & 3 & 4 \\15 & 2 & 8 \\13 & 4 & 9 \\8 & 0 & 6 \\\hline\end{array}$$

A)Yes
B)No

Question 43

Solve the problem.

-An industrial psychologist is investigating the effects of work environment on employee attitudes. A group of 20 recently hired sales trainees were randomly assigned to one of four different "home rooms" - five trainees per room. Each room is identical except for wall color. The four colors used were light green, light blue, gray and red. The psychologist wants to know whether room color has an effect on attitude, and, if so, wants to compare the mean attitudes of the trainees assigned to the four room colors. At the end of the training program, the attitude of each trainee was measured on a 60-point scale (the lower the score, the poorer the attitude). Give the null hypothesis.

A)The 20 sales trainees have the same attitude score.
B)The four rooms with different colors do not all have the same mean attitude score.
C)The five trainees in one room have the same mean attitude score as the five in a different room.
D)The four rooms with different colors have the same mean attitude score.

Question 44

Use software to conduct the analysis of variance test. Use a significance level of 0.05 to test the null hypothesis.

-A consumer magazine wants to compare the lifetimes of ballpoint pens of three different types. The magazine takes a random sample of pens of each type in the following table.
$\begin{array}{ccc} \underline{\text { Brand } 1}& \underline{ \text { Brand } 2}& \underline{ \text { Brand } 3}\\ 260 & 181 & 238 \\218 & 240 & 257 \\184 & 165 & 241 \\219 & 218 & 213\end{array}$
Do the data indicate that there is a difference in mean lifetime for the three brands of ballpoint pens?

A)Yes
B)No

Question 45

Solve the problem.

-A certain HMO is attempting to show the benefits of managed care to an insurance company. The HMO believes that certain types of doctors are more cost-effective than others. One theory is that Certification Level is an important factor in measuring the cost-effectiveness of physicians. To investigate this, the HMO obtained independent random samples of 20 physicians from each of the three certification levels-- Board certified (C); uncertified, board eligible (E); and Uncertified, board ineligible (I)-- and recorded the total per-member,per-month charges for each (a total of 60 physicians). In order to compare the mean charges for the three groups, the data will be subjected to an analysis of variance.
Write the alternative hypothesis tested by the ANOVA.

A)The three certification levels do not all have the same mean charge.
B)The three certification levels do not have the same mean charge.
C)The 60 physicians all have the same charge.
D)One certification group has the same mean charge as a different certification group.

Question 46

Use software to conduct the analysis of variance test. Use a significance level of 0.05 to test the null hypothesis.

-Random samples of four different models of cars were selected and the gas mileage of each car was measured. The results are shown below. $\begin{array}{cccc} \underline{\text { Model A}}& \underline{\text { Model B}}& \underline{\text { Model C}}& \underline{\text { Model D }}\\ 21 & 28 & 30 & 25 \\25 & 26 & 28 & 26 \\24 & 29 & 32 & 25 \\26 & 30 & 27 & 28\end{array}$
Do the data indicate that there is a difference in mean mileage for the different car models?

A)Yes
B)No

Question 47

Solve the problem.

-Four different leadership styles (A, B, C, and D)used by Big-Six accountants were investigated. As part of a designed study, 15 accountants were randomly selected from each of the four leadership style groups (a total of 60 accountants). Each accountant was asked to rate the degree to which their subordinates performed substandard field work on a 10-point scale -- called the "substandard work scale". The objective is to compare the mean substandard work scales of the four leadership styles. The data on substandard work scales for all 60 observations were subjected to an analysis of variance.

$$\begin{array}{l}\text { ONE-WAY ANOVA FOR SUBSTAND BY STYLE }\\\begin{array} { l | c | r | r | r | r } { \text { Source } } & \text { DF } & { \text { SS } } & { \text { MS } } & \text { F } & \text { P-value } \\\hline \text { Between Groups } & 3 & 3440.35 & 1146.784 & 6.050 & 0.0012 \\\text { Within Groups } & 56 & 10,614.86 & 189.551 & & \\\text { Total } & 59 & 14,055.21 & & &\end{array}\end{array}$$
Is there sufficient evidence to support the claim that the means of the four leadership style groups are not all the same?
Assume that a 0.05 significance level is used.

A)Yes
B)No

Question 48

Solve the problem.

-An industrial psychologist is investigating the effects of work environment on employee attitudes. A group of 20 recently hired sales trainees were randomly assigned to one of four different "home rooms" - five trainees
Per room. Each room is identical except for wall color. The four colors used were light green, light blue, gray and red. The psychologist wants to know whether room color has an effect on attitude, and, if so, wants to compare the mean attitudes of the trainees assigned to the four room colors. At the end of the training program, The attitude of each trainee was measured on a 60-pt. scale (the lower the score, the poorer the attitude). The data was subjected to a one-way analysis of variance. $$\begin{array}{l}\text { ONE-WAY ANOVA FOR ATTITUDE BY COLOR }\\\begin{array} { l | c | r | r | r | r } { \text { SOURCE } } & \text { DF } & { \text { SS } } & { \text { MS } } & { \text { F } } & \text { P-value } \\\hline \text { Between Groups } & 3 & 1678.15 & 559.3833 & 59.03782 & 0.8124 \\\text { Within Groups } & 16 & 151.6 & 9.475 & & \\\text { Total } & 19 & 1829.75 & & &\end{array}\end{array}$$
Based on this test, is there sufficient evidence to support the claim that the population means are not equal? Assume that
A 0.05 significance level is used.

A)Yes
B)No

Question 49

Solve the problem.
Identify the P-value in this display.

A)0.870
B)4.500
C)5.17
D)0.011

Question 50

Use software to conduct the analysis of variance test. Use a significance level of 0.05 to test the null hypothesis.

-The data below represent the weight losses for people on three different exercise programs.
$\begin{array}{ccc} \underline{\text { Exercise A}}& \underline{\text { Exercise B}}& \underline{\text { Exercise C }}\\2.5 & 5.8 & 4.3 \\8.8 & 4.9 & 6.2 \\7.3 & 1.1 & 5.8 \\9.8 & 7.8 & 8.5 \\5.1 & 1.2 & 7.9\end{array}$
Do the data indicate that there is a difference in mean weight loss for the three exercise programs?

A)Yes
B)No