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2

Question 1

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.
     
Do the data indicate that there is a difference in mean mileage for the different car models?
◦ Yes
◦ No

Question 2

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?  


◦ Yes
◦ No
4

Question 1

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.
   
Do the data indicate that there is a difference in mean lifetime for the three brands of ballpoint pens?
◦ Yes
◦ No

Question 2

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.
     
Do the data indicate that there is a difference in mean weight loss  for the three exercise programs?
◦ Yes
◦ No
6
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.

    ONE-WAY ANOVA FOR ATTITUDE BY COLOR


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.
◦ Yes
◦ No
8

Question 1

Solve the problem.



Identify the P-value in this display.
◦ 4.500
◦ 0.870
◦ 0.011
◦ 5.17

Question 2

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.

ONE-WAY ANOVA FOR SUBSTAND BY STYLE



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.
◦ Yes
◦ No
9
The three certification levels do not all have the same mean charge.
10
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.
◦ The three certification levels do not have the same mean charge.
◦ The 60 physicians all have the same charge.
◦ One certification group has the same mean charge as a different certification group.
◦ The three certification levels do not all have the same mean charge.