A recent study focused on the amount of money single men and women save monthly. The information is summarized here. Assume that the population standard deviations are unknown but equal.

Sample

Size Sample

Mean Population Standard

Deviation Men 25 50 10 Women 30 54 5

At the 0.01 significance level, what is your conclusion about whether women save more money than men?

Group of answer choices

A.Reject the null hypothesis and conclude that women save more than men.

B.Reject the null hypothesis and conclude that women and men save the same amount.

C.Fail to reject the null hypothesis.

D.Fail to reject the null hypothesis and conclude the means are different.

2.A random sample of 85 supervisors revealed that they worked an average of 8.5 years before being promoted. The population standard deviation was 3.7 years. Using the 0.95level of confidence, what is the confidence interval for the population mean?

Group of answer choices

A.8.56 and 10.42

B.5.72 and 9.58

C.7.71 and 9.29

D.8.06 and 9.92

3.An investigation of the effectiveness of a training program to improve customer relationships included a pre-training and a post-training customer survey. To compare the differences, they computed post-training survey score pre-training survey score. Seven customers were randomly selected and completed both surveys. The results are shown here.

Customer Pre-training Survey Post-training

Survey A 7 10

B 5 9

C 11 12

D 7 9

E 6 10

F 5 8

G 3 7

What is the value of the test statistic?

Group of answer choices

A.6.275

B.6.227

C.6.874

D.6.779

4.A national manufacturer of ball bearings is experimenting with two different processes for producing precision ball bearings. It is important that the diameters be as close as possible to an industry standard. The output from each process is sampled, and the average error from the industry standard is measured in millimeters. The results are presented here.

Process A Process B

Sample mean 7.00 8.00

Standard deviation 1.00 0.5

Sample size 17 19

The researcher is interested in determining whether there is evidence that the two processes yield different average errors. Assume that Process A is the first population. The population standard deviations are unknown but are assumed equal. What are the degrees of freedom?

Group of answer choices

A.15

B.18

C.36

D.34

5.The results of a mathematics placement exam at two different campuses of Mercy College follow:

Campus Sample Size Sample Mean Population Standard Deviation

1 330 33 8

2 310 31 7

The college wants to test the hypothesis that the mean score on Campus 1 is higher than on Campus 2. If we test the null hypothesis at the 5% level of significance, what is the decision?

Group of answer choices

A. Fail to reject the null hypothesis and conclude the means are the same.

B.Reject the null hypothesis and conclude the means are the same.

C.Fail to reject the null hypothesis and conclude the means are different.

D.Reject the null hypothesis and conclude the means are different.

E.Fail to reject the null hypothesis and conclude the means are the same.

F.Fail to reject the null hypothesis and conclude the means are different.