Probability using normal distribution.
A study of long distance phone calls made from corporate offices of the Pepsi Bottling Group, Inc., In Somers, New York, showed the calls follow the normal distribution. The mean length of time per call was 4.2 minutes and the standard deviation was 0.06 minutes.
a. What fraction of the calls last between 4.2 and 5 minutes?
b. What fraction of the calls last more than 5 minutes?
c. What fraction of the calls last between 5 and 6 minutes?
d. What fraction of the calls last between 4 and 6 minutes?
e. As part of her report to the president, the Director of Communications would like to report length of the longest (in duration) 4 percent of calls. What is the time?