Refer to Exercise 10.27. In addition to the compartment pressures, the level of creatine phosphokinase (CPK) in blood samples, a measure of muscle damage, was determined for each of 10 runners and 10 cyclists before and after exercise.7 The data summary-CPK values in units/liter-is as follows:

a. Test for a significant difference in mean CPK values for runners and cyclists before exercise under the assumption that σ21 ‰  σ22; use α = .05. Find a 95% confidence interval estimate for the corresponding difference in means.
b. Test for a significant difference in mean CPK values for runners and cyclists after exercise under the assumption that σ21 ‰  σ22; use α = .05. Find a 95% confidence interval estimate for the corresponding difference in means.
c. Test for a significant difference in mean CPK values for runners before and after exercise.
d. Find a 95% confidence interval estimate for the difference in mean CPK values for cyclists before and after exercise. Does your estimate indicate that there is no significant difference in mean CPK levels for cyclists before and after exercise?

Transcribed Image Text:

Runners Cyclists Standard Standard MDeviation Mea Devation Condition Before Exercise 255.63 115.48 173.8 60.69 After Exercise 28475 132.64 177. 64.53 Difference 29.13 21.01 3.3 6.85