References about this question: The t Test for Independent Means; The Distribution of Differences between Means; Estimating the Population Variance; Hypothesis Testing with a t Test for Independent Means; Assumptions of the t Test for Independent Means; Effect Size and Power for the t Test for Independent Means

Question: A researcher at a company wanted to know if workers' health would improve if they were given extra days off. Workers received two physical exams and an overall health rating (higher scores mean better health).The researcher selected five workers at random and gave each an additional 2 days off every month over the period between health exams. She then compared the health scores on the two exams.Use the .05 level.Which test would you use in this study?

Worker Before After

A 75 81

B 66 67

C 44 46

D 86 88

E 89 89

a. t-test for single sample

b. t-test for dependent means

c. t-test for independent means

d. Z test

In the experiment above, what is the mean of the comparison distribution?

a. 2.2

b. 0

c. 5.2

d. 81

e. 4

In the experiment above, what is the mean of the difference scores?

a. 2.2

b. 1.3

c. 81

d. 99

e. 2.9

In the experiment above, what is S²?

a. 1.04

b. 2.13

c. 1.3

d. .78

e. 5.2

In the experiment above, what is ²?

a. 1.04

b. 2.13

c. 1.3

d. .78

e. 5.2

In the experiment above, what is ?

a. 1.04

b. 2.11

c. 1.7

d. 1.02

e. 2.8

In the experiment above, what is df?

a. 1

b. 6

c. 9

d. 4

e. 5

In the experiment above, what is the cutoff sample score tcutoff?

a. 2.737

b. 1.137

c. 2.132

d. 3.112

e. 2.012

In the experiment above, what is the value of t?

a. 2.16

b. 2.11

c. 1.16

d. -2.14

e. -2.24

In the experiment above, what do you do with the hypothesis?

a. Reject the null hypothesis

b. Fail to reject null hypothesis

c. Reject the research hypothesis

d. Results are inconclusive