Suppose that a 1-gallon can of paint covers 513.3 square feet on average with a standard deviation of 31.5 square feet. (a) What is the probability that the sample mean area covered by a sample of 40...

Suppose that a 1-gallon can of paint covers 513.3 square feet on average with a standard deviation of 31.5 square feet.
(a) What is the probability that the sample mean area covered by a sample of 40 of these 1-gallon cans will be more than 520 square feet?
(b) What is the probability that the sample mean area covered by a sample of 40 of these 1-gallon cans will be anywhere between 510 to 520 square feet?