The weight of adult males has a mean of 65 kg and a standard deviation of 20 kg. The distribution is not normal. Suppose that a sample of size 16 is big enough for the central limit theorem to apply to the average weight of a random sample of adult males.

(a) What is the probability that the average weight of 16 randomly selected males will exceed 75 kg?

(b) Find the 90% range within which the average weight of a random sample of 16 adult males will lie.

(c) Find the 90% range if the random sample was 100 adult males.