Question

3. Consider a Phase II clinical trial designed to investigate the effectiveness of a new drug to reduce symptoms of asthma in children. A total of n=10 participants are randomized to receive either the new drug or a placebo. Participants are asked to record the number of episodes of shortness of breath over a 1 week period following receipt of the assigned treatment. The data are shown below.

Placebo: 7, 2, 10, 5, 12

New Drug: 3, 6, 4, 11, 1

Is there a difference in the number of episodes of shortness of breath over a 1 week period in participants receiving the new drug as compared to those receiving the placebo? By inspection, it appears that participants receiving the placebo have more episodes of shortness of breath, but is this statistically significant? We wish to test the following hypothesis test.

H0: The two populations are equal

vs

HA: The two populations are not equal

Conduct a Wilcoxon rank sum test and compute the observed test statistics and p-value. Draw a conclusion using α = 0.05.

Answer 1

p-value = 0.4206 > alpha

we fail to reject the null hypothesis