On a calm day on the campus of The Ohio State University, a kicker alternated between kicking a helium-filled football and an air-filled football. Each ball was kicked 39 times. It is possible that the kicker would either increase the distance of the kicks with practice or decrease the distance of the kicks due to fatigue. To avoid any bias of this nature, the balls were kicked in pairs, alternating between the helium-filled and air-filled balls with each kick. The difference in the distance the two balls were kicked in each of the 39 trials was recorded. After deleting the unsuccessful kicks where the ball did not travel very far forward, the researchers determined that the sample test statistic was to =1.555 and the P-value for a two-tailed hypothesis test was 0.0646. (Source: |ib.stat.cmu.edu/DASL/Stories/Heliumfootball.html) a. Why are these matched-pairs data? b. Is there a difference in the mean distance traveled in the helium and air-filled footballs at the o: = 0.05 level of significance