The lengths of lumber a machine cuts are normally distributed with a mean of 103 inches and a standard deviation of 0.4 inch (a) What is the probability that a randomly selected board cut by the machine has a length greater than 103.18 inches? (b) A sample of 41 boards is randomly selected. What is the probability that their mean length is greater than 103.18 inches? (a) The probability to (Round to four decimal places as needed.) (b) The probability is (Round to four decimal places as needed)