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 α = .05.

10. The critical value is

A) 3.162

B) 1.645

C) 2.776

D) 2.132

11. The test statistic is

A) 3.162

B) 1.645

C) 1.860

D) 2.132

12. Which of the following is a reasonable conclusion?

A) The Old Way takes more time than the New Way

B) There is not enough evidence to conclude that one method is faster than the other.

C) The New Way take more time than the Old Way.

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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.

13. Normality may be assumed because

A) the population may be assumed normal.

B) the population may be assumed large.

C) the samples may be assumed random.

D) nπ ≥ 10, n(1-π) ≥ 10 for both samples.

14. The test statistic is:

A) -1.96

B) -2.58

C) -4.00

D) -3.477

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

A) clearly reject the hypothesis of equal proportions.

B) barely reject the hypothesis of equal proportions.

C) barely accept the hypothesis of equal proportions.

D) clearly accept the hypothesis of equal proportions.

4. If you have 4 factors (call them A, B, C and D) in an ANOVA experiment with replication you could have 4 different two-factor interactions.

True

False

5. Use the following scenario to answer questions 5 to 12.

Sound engineers studied factors that might affect the output (in decibels) of a rock concert speaker system. The desired level of significance was α = .05. The results of their ANOVA tests are shown.The number of positions tested was

A) 1

B) 2

C) 3

D) 4

6. The number of amplifiers tested was

A) 1

B) 2

C) 3

D) 4

E) 24

7. The number of observations was

A) 16

B) 19

C) 23

D) 24

8. The number of observations per cell was

A) 1

B) 2

C) 3

D) 4

9. The effect of amplifier was

A) significant.

B) insignificant.

10. The effect of position was

A) significant.

B) insignificant.

C) borderline.

11. The F statistic for amplifier was

A) 10.16

B) 9.90

C) 5.72

12. The interaction was

A) significant.

B) insignificant.

C) borderline.

Use the following scenario to answer questions 13 to 15.

Three randomly-chosen pieces of four types of PVC pipe of equal wall thickness are tested to failure to determine the burst strength (in pounds per square inch) under three temperature conditions, yielding the results shown below.

13. Which test would be appropriate?

A) two-factor ANOVA with replication.

B) one-factor ANOVA.

C) dependent (paired samples) t-test.

D) two-factor ANOVA no replication.

14. Total degrees of freedom would be

A) 19

B) 12

C) 35

D) 59

15. An interaction test would be appropriate.

A) True.

B) False