CRA CDs Inc wants the mean lengths of the cuts on a CD to be

CRA CDs Inc. wants the mean lengths of the \"cuts\" on a CD to be 134 seconds (2 minutes and 14 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 5 seconds. Suppose we select a sample of 16 cuts from various CDs sold by CRA CDs Inc.

What percent of the sample means will be greater than 136 seconds? (Round your z-value to 2 decimal places and final answer to 2 decimal places.)

What percent of the sample means will be greater than 128 seconds? (Round your answer to 2 decimal places.)

What percent of the sample means will be greater than 128 but less than 136 seconds? (Round your z-value to 2 decimal places and final answer to 2 decimal places.)

Solution