Problem 1. Analyze the following data set from a clinical trial using SAS. You
should address the following issues:
(i) Summarize the data in both groups using descriptive statistics. Do the data appear
normally distributed?
(ii) Perform a t-test of the null hypothesis that the means of the two groups are equal.
Draw conclusions.
(iii) Repeat (ii) using a Wilcoxon test.
(iv) Which test is more appropriate for these data and why?
Attach your SAS program and cut and paste relevant output. Do not turn in your entire
output unedited!
Data set:
Human beta-endorphin (HBE) is a hormone secreted by the pituitary gland under
conditions of stress. It has been hypothesized that regular exercisers have different HBE
blood levels at rest. Twenty-six sedentary men were randomly assigned to one of two
groups: group 1 (intervention; n = 11) were given physical fitness training for 3 weeks;
group 2 (control; n = 15) were not given any training. At the end of the three weeks, the
following HBE blood levels were observed:
Group 1: 39, 40, 32, 60, 19, 52, 41, 32, 13, 37, 28
Group 2: 70, 47, 54, 27, 31, 42, 37, 41, 9, 18, 33, 23, 49, 41, 59
