An apple juice producer sources his apples from a large grove. The amount of juice extracted from a single apple is normally distributed with mean 141 ml and standard deviation 12 ml.
(a) What is the probability that a randomly-chosen apple will contain less than 150 ml of juice?
(b) What amount of juice would only 1 in 100 apples exceed?
(c) Describe the probability distribution of the average amount of juice from a sample of 20 apples? What is the probability that this average is less than 150ml?