A hospital is comparing three different drugs to determine if there is a difference in the number of hours of pain relief each provides on average for patients with pain after surgery. The mean pain relief (in hours) for each drug and SPSS ANOVA output are given below.

Drug Mean pain relief

1 8.28

2 7.52

3 8.36

a) Does the average length of pain relief differ between any of the drugs? State the appropriate hypotheses for this test.

b) Give the values of the test statistic and P-value, and your conclusion for the test. Use? = 0.05.

c) Would it be appropriate to perform a Bonferroni test to see if any of the drugs differ in the mean hours of pain relief? Explain.

d) Describe a well designed experiment to obtain this data.

ANOVA time Sum of Squares df Mean Square F Sig. Between Groups 3.385 2 1.693 2.662 093 Within Groups 13.352 21 .636 Total 16.737 23 Multiple Comparisons Dependent Variable: time Bonferroni Mean 95% Confidence Interval Difference (1- (1) Drug (J) Drug J) Std. Error Sig. Lower Bound Upper Bound 1.00 2.00 75903 38746 191 -.2489 1.7669 3.00 -.07937 40185 1.000 -1.1247 9660 2.00 1.00 -.75903 .38746 191 -1.7669 2489 3.00 -.83839 41269 165 -1.9119 2352 3.00 1.00 07937 40185 1.000 -.9660 1.1247 2.00 83839 41269 165 -.2352 1.9119