1. One-Way Analysis of Variance: Comparing Several Means BPS chapter 25 © 2006 W.H. Freeman and Company

2. Analysis of variance True or false: The Analysis of Variance (ANOVA) approach for comparing 4 different means will require all of the following separate comparisons: a) True b) False

3. Analysis of variance (answer) True or false: The Analysis of Variance (ANOVA) approach for comparing 4 different means will require all of the following separate comparisons: a) True b) False

4. Analysis of variance True or false: The alternative hypothesis in ANOVA is: a) True b) False

5. Analysis of variance (answer) True or false: The alternative hypothesis in ANOVA is: a) True b) False

6. Analysis of variance True or false: If the null hypothesis is false, the observed variability in the sample means will be greater than the variability you would expect if the means are equal. a) True b) False

7. Analysis of variance (answer) True or false: If the null hypothesis is false, the observed variability in the sample means will be greater than the variability you would expect if the means are equal. a) True b) False

8. Analysis of variance True or false: The P-value for an ANOVA will be small when the F test statistic is large. a) True b) False

9. Analysis of variance (answer) True or false: The P-value for an ANOVA will be small when the F test statistic is large. a) True b) False

10. ANOVA test Researchers performed a double-blind study on the effects of a nonsteroidal anti-inflammatory drug (NSAID) given before and after arthroscopic knee surgery. A sample of 83 patients undergoing elective knee arthroscopy were randomly divided into three treatment groups. Group 1 was given the drug before and after surgery. Group 2 was given a placebo before surgery and the drug after. Group 3 was given the placebo before and after surgery. Researchers compared the mean pain scores of the patients in the three treatment groups one day after surgery. What is the appropriate null hypothesis for this study? a) b) c) d)

11. ANOVA test (answer) Researchers performed a double-blind study on the effects of a nonsteroidal anti-inflammatory drug (NSAID) given before and after arthroscopic knee surgery. A sample of 83 patients undergoing elective knee arthroscopy were randomly divided into three treatment groups. Group 1 was given the drug before and after surgery. Group 2 was given a placebo before surgery and the drug after. Group 3 was given the placebo before and after surgery. Researchers compared the mean pain scores of the patients in the three treatment groups one day after surgery. What is the appropriate null hypothesis for this study? a) b) c) d)

12. ANOVA test Researchers performed a double-blind study on the effects of a nonsteroidal anti-inflammatory drug (NSAID) given before and after arthroscopic knee surgery. A sample of 83 patients undergoing elective knee arthroscopy were randomly divided into three treatment groups. Group 1 was given the drug before and after surgery. Group 2 was given a placebo before surgery and the drug after. Group 3 was given the placebo before and after surgery. Researchers compared the mean pain scores of the patients in the three treatment groups one day after surgery. What is the appropriate alternative hypothesis for this study? a) b) c) d) e)

13. ANOVA test (answer) Researchers performed a double-blind study on the effects of a nonsteroidal anti-inflammatory drug (NSAID) given before and after arthroscopic knee surgery. A sample of 83 patients undergoing elective knee arthroscopy were randomly divided into three treatment groups. Group 1 was given the drug before and after surgery. Group 2 was given a placebo before surgery and the drug after. Group 3 was given the placebo before and after surgery. Researchers compared the mean pain scores of the patients in the three treatment groups one day after surgery. What is the appropriate alternative hypothesis for this study? a) b) c) d) e)

14. ANOVA test Researchers performed a double-blind study on the effects of a nonsteroidal anti-inflammatory drug (NSAID) given before and after arthroscopic knee surgery. A sample of 83 patients undergoing elective knee arthroscopy were randomly divided into three treatment groups. Using the output below, what is the F-statistic for the ANOVA comparing the mean pain scores of the three knee surgery treatment groups one day after surgery? a) 0.012 b) 4.79 c) 2553 d) 23.10

15. ANOVA test (answer) Researchers performed a double-blind study on the effects of a nonsteroidal anti-inflammatory drug (NSAID) given before and after arthroscopic knee surgery. A sample of 83 patients undergoing elective knee arthroscopy were randomly divided into three treatment groups. Using the output below, what is the F-statistic for the ANOVA comparing the mean pain scores of the three knee surgery treatment groups one day after surgery? a) 0.012 b) 4.79 c) 2553 d) 23.10

16. ANOVA test Researchers performed a double-blind study on the effects of a nonsteroidal anti-inflammatory drug (NSAID) given before and after arthroscopic knee surgery. A sample of 83 patients undergoing elective knee arthroscopy were randomly divided into three treatment groups. Using the output below, what is the P-value for the ANOVA comparing the mean pain scores of the three knee surgery treatment groups one day after surgery? a) 0.012 b) 4.79 c) 0.024 d) 0.006

17. ANOVA test (answer) Researchers performed a double-blind study on the effects of a nonsteroidal anti-inflammatory drug (NSAID) given before and after arthroscopic knee surgery. A sample of 83 patients undergoing elective knee arthroscopy were randomly divided into three treatment groups. Using the output below, what is the P-value for the ANOVA comparing the mean pain scores of the three knee surgery treatment groups one day after surgery? a) 0.012 b) 4.79 c) 0.024 d) 0.006

18. ANOVA test Using the output below, which of the following conclusions is correct regarding the mean pain score one day after surgery? Use  = 0.05. a) It does not differ significantly among the three treatment groups. b) It differs significantly among all three treatment groups. c) It is significantly lower for Group 1 compared to Group 3. d) It is significantly lower for Group 1 compared to Group 2.

19. ANOVA test (answer) Using the output below, which of the following conclusions is correct regarding the mean pain score one day after surgery? Use  = 0.05. a) It does not differ significantly among the three treatment groups. b) It differs significantly among all three treatment groups. c) It is significantly lower for Group 1 compared to Group 3. d) It is significantly lower for Group 1 compared to Group 2.