Statistics

1. The manager of a computer help desk operation has collected enough data to conclude that the distribution of time per call is normally distributed with a mean equal to 8.21 minutes and a standard deviation of 2.14 minutes. The manager has decided to have a signal system attached to the phone so that after a certain period of time, a sound will occur on his employees’ phone if he exceeds the time limit. The manager wants to set the time limit at a level such that it will sound on only 8 percent of all calls. What is the time limit should be?