The manager of a computer help desk operation in Moncton has collected enough data to conclude that the time per call is normally distributed with a mean equal to 8.21 minutes and a standard deviation of 2.14 minutes. The manager wants to set the time limit at a level such that it will sound on only 8 percent of all calls. The time limit should be
A) about 11.23 minutes
B) about 5.25 minutes
C) about 14.58 minutes
D) about 10.35 minutes
E) about 20.29 minutes

Question

Quizplus · Accepted Answer

To find the time limit that corresponds to the top 8% of calls, we need to find the z-score that corresponds to the 92nd percentile (100% - 8%). Using a standard normal distribution table, the z-score for 0.92 is approximately 1.41. Using the formula: time limit = mean + (z-score * standard deviation), we get 8.21 + (1.41 * 2.14) ≈ 11.23 minutes.

The Manager of a Computer Help Desk Operation in Moncton