1. Data are collected in a clinical trial evaluating a new compound designed to improve wound healing in trauma patients. The new compound is compared against placebo. After treatment for 5 days with the new compound or placebo, the extent of the wound healing is measured and the data are shown in Table 7-6. Is there a difference in the extent of wound healing by treatment? (Hint: Are treatment and the percent wound healing independent?) Run the appropriate test at a 5% level of significance.

Table 7-6: Data for Practice Problems 1 and 2

Treatment

0-25%

26-50%

51-75%

76-100%

New Compound (n=125)

15

37

32

41

Placebo (n=125)

36

45

34

10

2. Use the data in Problem 1 and pool the data across the treatments into one sample size n=250. Use the pooled data to test whether the distribution of the percent wound healing is approximately normal. Specifically, use the following distribution: 30%, 40%, 20%, and 10%. Run the appropriate test = 0.05.