NFL data from the 2013 football season reported the number of yards gained by each of the league's 181 wide receivers:

The mean is 426.98 yards, with a standard deviation of 408.34 yards.
a) According to the Normal model, what percent of receivers would you expect to gain more yards than 2 standard deviations above the mean number of yards?
b) For these data, what does that mean?
c) Explain the problem in using a Normal model here.