The lengths of lumber a machine cuts are normally distributed with a mean of

86

inches and a standard deviation of

0.6

inch.(a) What is the probability that a randomly selected board cut by the machine has a length greater than

86.17

inches?(b) A sample of

45

boards is randomly selected. What is the probability that their mean length is greater than

86.17

inches?

A. The Probability is __

B. The ProbBLITY IS_