A normal population has a mean of 73 and a standard deviation of 6. You select a sample of 40. Compute the probability the sample mean is (Round z values to 2 decimal places and final answers to 4 decimal places):
(a) Less than 72. Probability
(b) Between 72 and 74. Probability:
(c) Between 74 and 75. Probability:
(d) Greater than 75. Probability: