Question

Given the following dataset x   1   1   2   3   4   5

y   0   2   4   5   5   3

We want to test the claim that there is a correlation between xand y. The level of cretaine phosphokinase (CPK) in blood samples measures the amount of muscle damage for athletes. At Jock State University, the level of CPK was determined for each of 25 football players and 15 soccer players before and after practice. The two groups of athletes are trained independently. The data summary is as follows :For football players : n=25 before practice  after practice   difference(before-after)

mean   254.73   225.6   29.13

St.deviation   115.5   132.6   21.00

For soccer players

n=15   before practice   after practice   difference(before-after)

mean   177.1   173.8   3.3

st.deviation   60.7   64.4   6.88

7. Construct a 95% Confidence Interval for the difference in mean CPK values for foot-ball players and soccer players BEFORE exercises.

8. Construct a 95% Confidence Interval for the difference in mean CPK values for foot-ball players BEFORE and AFTER exercises.

9. Test the claim that the mean CPK level has DECREASED for soccer players AFTERexercise (compared to the mean BEFORE exercise), using α= 0.10.

10. AFTER practice, do football players have a DIFFERENT mean CPK values com-pared to soccer players? Test this claim by performing a hypothesis test, usingα= 0.10.

Answer 1