Hypothesis testing practice quiz

True/False Questions

1. N comparing the means of two independent samples if the test statistic indicates a significant difference at a=.05, it will also be significant at a=.10

2. For two independent samples, the comparison of means generally utilizes the student's t distribution

3. The F tests is used to compare the variances of two samples

4: The paired t-test utilizes a pooled variance when comparing the sample means

5: Performing a paired T-test is similar to performing a one sample t-test.

Multiple Choice Questions

6. Weekly sales of diet coke at twelve KMART stores are compared before and after installing a new eye- catching display. To determine if the display is effective in increasing sales, what type of statistical test would you perform?

7: Use the following scenario to answer questions 7 to 9.Carver Memorial Hospital's surgeons have a new procedure that they think will decrease the time to perform an appendectomy. A sample of 8 appendectomies using the old method had a mean of 38 minutes with a variance of 36 minutes, while a sample of 10 appendectomies using the experimental method had a mean of 29 minutes with a variance of 16 minutes. Use alpha = .10 for all tests. For a right-tail test of means (assume equal variances) the critical value is

8: For the means, the test statistic (assuming equal variances) is

A: 3.814 B: 2.365 C: 3.000 D: 1.895

9. To test for equal variances, the critical values are

10. Use the following scenario to answer questions 10 to 12.
In a test of a new surgical procedure, five 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 time (in minutes) to complete each procedure was carefully recorded. Use a right-tail test at alpha = .05.

12: Which of the following is a reasonable conclusion?

13: Use the following scenario to answer questions 13 to 15. 
The Board of Surgeons recommends a postoperative examination six months after a prostatectomy. In a sample from the records of Carver Memorial Hospital, follow-up exams were given in 80 out of 200 cases. In a sample of records from HiRent Hospital, follow-up exams were given in 120 out of 200 cases.
Normality might be assumed because

15: If we are using alpha = .01 and a left-tailed test the decision is