CRA CDs Inc. wants the mean lengths of the "cuts" on a CD to be 165 seconds (2 minutes and 45 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 a normal distribution with a standard deviation of fifteen seconds. Suppose that we select a sample of 25 cuts from various CDs sold by CRA CDs Inc. Use Appendix B.1 for the z values.

a. What can we say about the shape of the distribution of the sample mean?

Shape of the distribution is (Click to select) Normal Uniform Binomial

b. What is the standard error of the mean? (Round the final answer to 2 decimal places.)

Standard error of the mean seconds.

c. What percentage of the sample means will be greater than 169 seconds? (Round the z values to 2 decimal places and the final answers to 2 decimal places.)

Percentage %

d. What percentage of the sample means will be greater than 158 seconds? (Round the z values to 2 decimal places and the final answers to 2 decimal places.)

Percentage %

e. What percentage of the sample means will be greater than 158 but less than 169 seconds? (Round the z values to 2 decimal places and the final answers to 2 decimal places.)

Percentage %