Tom works for a fruit company and found that the weights of pineapples are normally distributed with mean = 500 grams and standard deviation = 100 grams.
a. If he randomly chooses 16 pineapples and measures their weights, what is the probability that the average weight x¯ is more than 475 grams?
b. For a random sample of 16 pineapples, find the probability that the sample standard deviation s will exceed 129 grams.