The diameter of a brand of ping-pong ball is approximately normally distributed, with a mean of 1.30 inches and a standard deviation of 0.04 inch. If you select a random sample of 16 ping-pong balls,
(a) What is the sampling distribution of the mean?
(b) What is the probability that the sample mean is less than 1.28 inches?
(c) what is the probability that the sample mean is between 1.31 and1.33 inches?
(d) The probability is 60% that the sample mean is between will be between what two values, symmetrically distributed around the population mean?