Question

Question 2: In the Payne County medical center, a surgical director selected a random sample of 37 nurses and found that the mean of their ages was 39.40. The sample standard deviation for the ages is 6.42. The director also selected a random sample of 32 physical therapists and found the mean of their ages was 36.77.

The sample standard deviation of ages for the physical therapists is 4.48.

A. [3] Give one reason why this data should not be analyzed as matched pairs.

B. [7] Find the 99% confidence interval of the differences in the average ages.
Group 1 is the nurses; group 2 is the physical therapists.
Assume that variances are unpooled; Satterthwaite’s formula gives DF = 64.285.

C. [3] Based on your interval, would you support or reject a hypothesis that nurses and physical therapists have the same average age? Briefly explain your reasoning. [If you didn’t find a confidence interval, use an interval from –1.11 to +6.08.]

Answer 1