he 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...

he 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:

For soccer players:

Assume that all the data above are normal

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

 AFTER practice, do football players have a DIFFERENT mean CPK values compared to soccer players? Test this claim by performing a hypothesis test, using α=0.10.