Question 1

Random samples of Tuesday and Friday withdrawals from a college-campus ATM were compared to see whether or not there was a difference in the means.The results shown below are from MegaStat.Analyze these results thoroughly.

Accepted Answer

The answer of Random samples of Tuesday and Friday withdrawals...

Question 2

Two well-known aviation training schools are being compared using random samples of their graduates.It is found that 70 of 140 graduates of Fly-More Academy passed their FAA exams on the first try,compared with 104 of 260 graduates of Blue Yonder Institute.To compare the pass rates,the pooled proportion would be:

Accepted Answer

A)  .500 
B)  .435 
C)  .400 
D)  .345

Question 3

In a random sample of patient records in Cutter Memorial Hospital,six-month postoperative exams were given in 90 out of 200 cases,while in Paymor Hospital such exams were given in 110 out of 200 cases.The pooled proportion is:

Accepted Answer

A)  .50 
B)  .40 
C)  .30 
D)  .20

Question 4

A medical researcher wondered if there is a significant difference between the mean birth weight of boy and girl babies.Random samples of 5 babies' weights (pounds)for each gender showed the following: To test the researcher's hypothesis,we should use the:

Accepted Answer

A)  paired (dependent)samples t-test. 
B)  independent samples t-test. 
C)  large-sample z-test. 
D)  t-test for correlation.

Question 5

In a random sample of patient records in Cutter Memorial Hospital,six-month postoperative exams were given in 90 out of 200 prostatectomy patients,while in Paymor Hospital such exams were given in 110 out of 200 cases.In a left-tailed test for equality of proportions,the p-value is:

Accepted Answer

A)  .9772 
B)  .0228 
C)  .4772 
D)  .0517

Question 6

The F test is used to test for the equality of two population variances.

Accepted Answer

A) True 
 B)False

Question 7

Which is not true of the two-tailed F-test for equality of variances?

Accepted Answer

A)  It requires reversing the numerator and denominator d.f.to obtain the left-tail critical value. 
B)  It can be avoided by "folding" the larger variance into the numerator and adjusting F1F1F1S1F1F1F10. 
C)  It is fairly robust to the presence of nonnormality in the populations being sampled.

Question 8

Two well-known aviation training schools are being compared using random samples of their graduates.It is found that 70 of 140 graduates of Fly-More Academy passed their FAA exams on the first try,compared with 104 of 260 graduates of Blue Yonder Institute.In a right-tailed test,the p-value is .0275,so at F1F1F1S1F1F1F10 = .025 we should:

Accepted Answer

A)  reject the hypothesis of equal proportions. 
B)  not reject the hypothesis of equal proportions. 
C)  change the F1F1F1S1F1F1F10 to .05 to get a rejection.

Question 9

A corporate analyst is testing whether mean inventory turnover has increased.Inventory turnover in six randomly chosen product distribution centers (PDCs)is shown. The degrees of freedom for the appropriate test would be:

Accepted Answer

A)  6. 
B)  5. 
C)  4. 
D)  12.

Question 10

At Huge University,a sample of 200 business school seniors showed that 26 planned to pursue an MBA degree,compared with 120 of 800 arts and sciences seniors.We want to know if the proportion is higher in the arts and sciences group.The p-value for a left-tailed test is approximately:

Accepted Answer

A)  .38 
B)  .48 
C)  .24 
D)  .51

Question 11

In a test of a new surgical procedure,the five most respected surgeons in FlatBroke Township were invited to Carver Hospital.Each surgeon was assigned two patients of the same age,gender,and overall health.One patient was operated upon in the old way,and the other in the new way.Both procedures are considered equally safe.The surgery times are shown below: The time (in minutes)to complete each procedure was carefully recorded.In a right-tailed test for a difference of means,the test statistic is:

Accepted Answer

A)  3.162 
B)  1.645 
C)  1.860 
D)  2.132

Question 12

John wants to compare two means.His sample statistics were and .Assuming equal variances,the pooled variance is:

Accepted Answer

A)  4.5 
B)  4.9 
C)  5.1 
D)  3.8

Question 13

A corporate analyst is testing whether mean inventory turnover has increased.Inventory turnover in six randomly chosen product distribution centers (PDCs)is shown. The value of the test statistic is:

Accepted Answer

A)  3.798 
B)  2.449 
C)  1.225 
D)  3.503

Question 14

A medical researcher compared the variances in birth weights for five randomly chosen babies of each gender,with the MegaStat results shown below. The population variances:

Accepted Answer

A)  may be assumed equal at any customary F1F1F1S1F1F1F10. 
B)  should be assumed unequal at any customary F1F1F1S1F1F1F10. 
C)  are not relevant to this paired t-test.

Question 15

When using independent samples to test the difference between two population means,it is desirable but not necessary for the sample sizes to be the same.

Accepted Answer