An August 2001 article in the journal Medicine and Science in Sports and Exercise compared how long it would take men and women to burn 200 calories during light or heavy workouts on various kinds of exercise equipment. The results summarized in the table are the average times for a group of physically active young men and women whose performances were measured on each type of equipment.
a) On average, how many minutes longer than a man must a woman exercise at a light exertion rate in order to burn 200 calories? Give a 95% confidence interval.
b) Estimate the average number of minutes longer a woman must work out at light exertion than at heavy exertion to get the same benefit. Give a 95% confidence interval.
c) These data are actually averages rather than individual times. How might this affect the margins of error in these confidence intervals?
