Question

1. A pain killing drug was tested for efficiency in 52 women who were experiencing intestine cramping pain. 26 of the women were randomly allotted to receive the drug and the remaining 26 received a placebo. Capsules of drug or placebo where given before breakfast and again at noon. A pain relief scored based on hourly questioning through the day was computed for each woman. The possible pain relief scores ranged from 0 (no relief) to 56 (complete relief for 56 hours). Summary of scores is shown in the following:

Treatment             N                          Pain relief scores

                                                             Mean                               S.D.

Drug                       26                         31.96                               12.05

Placebo                 26                          25.32                               13.78

1. Test for evidence of efficiency of the drug with significance level of 0.05
2. Test if there is a difference in pain relief scores between both groups with a significance level of 0.05  

2. Explain using exercise 1a as an example of the following:

Null and alternative hypothesis, test statistics, significance level, critical and p-value. Use a graph.

Answer 1

a)