In January 2003, the American worker spent an average 77 hours logged on to the Internet while at work (CNBC, March 15, 2003). Assume that the population mean is 77 hours, the times are normally distributed, and the standard deviation is 20 hours.

A person is classified as a heavy user if he or she is in the upper 20% of usage. In January 2003, how many hours did a worker have to be logged on to the Internet to be considered a heavy user?