The weight of a sophisticated running shoe is normally distributed with a mean of 15 ounces.
(a) What must the standard deviation of weight be in order for the company to state that 98% of its shoes weight less than 16 ounces?
(b) Suppose that the standard deviation is actually 0.82. If we sample 6 such running shoes, find the probability that exactly 4 of those shoes weigh more than 16 ounces