A football coach wanted to determine whether his punter could kick a football filled with helium farther than a football filled with air, since helium is much lighter than air. Two identical footballs, one air-filled and one-helium filled, were tested outdoors on a windless day at an athletic complex.
The kicker, a novice punter, was not informed which football contained helium. Each football was kicked 40 times by the same person, and the two footballs were alternated with each kick (so that the punter’s leg would play no favorites if he tired or improved with practice). The experimenter recorded the distance traveled in yards by each ball. Each measurement was recorded to the nearest whole number of yards. Below are dot plots and box plots of the two sets of data: