CRA CDs Inc. wants the mean lengths of the "cuts" on a CD to be 155 seconds (2 minutes and 35 seconds). This will allow the disk jockeys to have plenty of time for commercials within each 10-minute segment. Assume the distribution of the length of the cuts follows the normal distribution with a population standard deviation of 10 seconds. Suppose we select a sample of 25 cuts from various CDs sold by CRA CDs Inc.
What percent of the sample means will be greater than 147 but less than 160 seconds?