TARLETON STATE UNIVERSITY

Chapter 8Homework Problems:

Emmert.S

[Pick the date]

1) A doctor is interested in determining whether a film about exercise will change 10

persons’ attitudes about exercise. The results of his questionnaire are shown. A higher numerical value shows a more favorable attitude toward exercise. Is there enough

evidence to support the claim, at alpha= 0.05, that there was a change in attitude?

(Complete the Proper Box for this study):

Paired Design Hypothesis: Test statistic= P-Value= Decision and conclusion:

Independent Design

a. Conduct an F- test of variances to determine whether to

use a pooled t-test or non-pooled t-test:

Test statistic F (3 decimal places) =_______ P-value (4 decimal places) =________

Conclusion (select one):

____There is evidence that the variances are different. ____ No evidence that the variances are different.

b. Based on your F-test of variances which test of means will

be conducted? (Select one)

____a pooled t-test ____ non-pooled t-test. c. Conduct the proper t-test selected above.

Hypothesis: Test statistic= P-Value= Decision and conclusion:

2) A researcher wanted to compare the pulse rates of identical twins to see whether there was any difference. Eight sets of twins were selected. The rates are given in the

table as number of beats per minute. At alpha=0.01, is there a significant difference in the average pulse rates of twins?

(Complete the Proper Box for this study):

Paired Design Hypothesis: Test statistic= P-Value= Decision and conclusion:

Independent Design

d. Conduct an F- test of variances to determine whether to

use a pooled t-test or non-pooled t-test:

Test statistic F (3 decimal places) =_______ P-value (4 decimal places) =________

Conclusion (select one):

____There is evidence that the variances are different. ____ No evidence that the variances are different.

e. Based on your F-test of variances which test of means will

be conducted? (Select one)

____a pooled t-test ____ non-pooled t-test. f. Conduct the proper t-test selected above.

Hypothesis: Test statistic= P-Value= Decision and conclusion:

3) The numbers of calories contained in –cup servings of randomly selected flavors of ice cream from two national brands are listed here. At the 0.05 level of significance, is there

sufficient evidence to conclude that the mean the number of calories differs between the two brands?

(Complete the Proper Box for this study):

Paired Design Hypothesis: Test statistic= P-Value= Decision and conclusion:

Independent Design

m. Conduct an F- test of variances to determine whether to

use a pooled t-test or non-pooled t-test:

Test statistic F (3 decimal places) =_______ P-value (4 decimal places) =________

Conclusion (select one):

____There is evidence that the variances are different. ____ No evidence that the variances are different.

n. Based on your F-test of variances which test of means will

be conducted? (Select one)

____a pooled t-test ____ non-pooled t-test. o. Conduct the proper t-test selected above.

Hypothesis: Test statistic= P-Value= Decision and conclusion:

4) The yearly tuition costs in dollars for random samples of medical schools that specialize in research and in primary care are listed. At = 0.05, can it be concluded

that a difference between the means of the two groups exists?

(Complete the Proper Box for this study):

Paired Design Hypothesis: Test statistic= P-Value= Decision and conclusion:

Independent Design

p. Conduct an F- test of variances to determine whether to

use a pooled t-test or non-pooled t-test:

Test statistic F (3 decimal places) =_______ P-value (4 decimal places) =________

Conclusion (select one):

____There is evidence that the variances are different. ____ No evidence that the variances are different.

q. Based on your F-test of variances which test of means will

be conducted? (Select one)

____a pooled t-test ____ non-pooled t-test. r. Conduct the proper t-test selected above.

Hypothesis: Test statistic= P-Value= Decision and conclusion:

5) A dietitian wishes to see if a person’s cholesterol level will change if the diet is supplemented by a certain mineral. Six subjects were pretested, and then they took the

mineral supplement for a 6-week period. The results are shown in the table. (Cholesterol level is measured in milligrams per deciliter) Can it be concluded that the cholesterol

level has been changed at alpha= 0.10? Assume the variable is approximately normally distributed.

(Complete the Proper Box for this study):

Paired Design Hypothesis: Test statistic= P-Value= Decision and conclusion:

Independent Design

g. Conduct an F- test of variances to determine whether to

use a pooled t-test or non-pooled t-test:

Test statistic F (3 decimal places) =_______ P-value (4 decimal places) =________

Conclusion (select one):

____There is evidence that the variances are different. ____ No evidence that the variances are different.

h. Based on your F-test of variances which test of means will

be conducted? (Select one)

____a pooled t-test ____ non-pooled t-test. i. Conduct the proper t-test selected above.

Hypothesis: Test statistic= P-Value= Decision and conclusion:

6) A physical education director claims by taking a special vitamin, a weight lifter can

increase his strength. Eight athletes are selected and given a test of strength, using the standard bench press. After 2 weeks of regular training, supplemented with the vitamin,

they are tested again. Test the effectiveness of the vitamin regimen at alpha= 0.05. Each value in these data represents the maximum number of pounds the athlete can

bench-press. Assume that the variable is approximately normally distributed.

(Complete the Proper Box for this study):

Paired Design Hypothesis: Test statistic= P-Value= Decision and conclusion:

Independent Design

j. Conduct an F- test of variances to determine whether to

use a pooled t-test or non-pooled t-test:

Test statistic F (3 decimal places) =_______ P-value (4 decimal places) =________

Conclusion (select one):

____There is evidence that the variances are different. ____ No evidence that the variances are different.

k. Based on your F-test of variances which test of means will

be conducted? (Select one)

____a pooled t-test ____ non-pooled t-test. l. Conduct the proper t-test selected above.

Hypothesis: Test statistic= P-Value= Decision and conclusion:

7) The weights in ounces of a sample of running shoes for men and women are shown. Calculate the variances for each sample, and test the claim that the means are different

at = 0.1.

(Complete the Proper Box for this study):

Paired Design Hypothesis: Test statistic= P-Value= Decision and conclusion:

Independent Design

s. Conduct an F- test of variances to determine whether to

use a pooled t-test or non-pooled t-test:

Test statistic F (3 decimal places) =_______ P-value (4 decimal places) =________

Conclusion (select one):

____There is evidence that the variances are different. ____ No evidence that the variances are different.

t. Based on your F-test of variances which test of means will

be conducted? (Select one)

____a pooled t-test ____ non-pooled t-test. u. Conduct the proper t-test selected above.

Hypothesis: Test statistic= P-Value= Decision and conclusion: