11. An exercise physiologist compares two cardiovascular fitness programs. Ten matched pairs of out-of-shape adult volunteers are formed on the basis of a variety of factors such as sex, age, weight, blood pressure, exercise, and eating habits. In each pair, one individual is randomly assigned to program 1 and the other to program 2. After four months, the individuals in the two programs are compared on several measures. The following are the results for resting pulse rate:

First testing : X1 ¼ 48:3 s1 ¼ 9:2 Second testing : X2 ¼ 50:1 s2 ¼ 11:1 r12 ¼ þ:81 Program 1: SX1 ¼ 762 SS1 ¼ 150:6 Program 2: SX2 ¼ 721 SS2 ¼ 129:9 r12 ¼ þ:46 316 Chapter 15 Comparing the Means of Dependent Samples

(a) Compute sX1X2

.

(b) Specify the statistical hypotheses.

(c) Perform the test (a ¼ :05).

(d) Draw final conclusions.