statistics
posted by Anonymous .
The number of viewers of American Idol has a mean of 21 million with a standard deviation of 10 million. Assume this distribution follows a normal distribution. Refer to the table in Appendix B.1. What is the probability that next week's show will:
(a) Have between 22 and 31 million viewers? (Round zscore computation to 2 decimal places and your final answer to 4 decimal places.)

Z = (scoremean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" (B1?) to find the proportions related to the Z scores.