The running coach conducts a hypothesis test and finds that running club members significantly improve their running times with a p-value < 0.05. the running coach wants to calculate how many seconds change to expect for runners who participate in running clubs. what is the best method for the running coach to use to determine how many seconds change to expect for runners who participate in running clubs? use the difference in sample means (530 − 520) in a hypothesis test for a difference in two population means (or treatment effect).