Exhibit 8-1 in Order to Estimate the Average Time Spent on the on the Computer

Multiple Choice

Exhibit 8-1
In order to estimate the average time spent on the computer terminals per student at a local university, data were collected for a sample of 81 business students over a one-week period. Assume the population standard deviation is 1.8 hours.
-Refer to Exhibit 8-1. If the sample mean is 9 hours, then the 95% confidence interval is

A) 7.04 to 110.96 hours
B) 7.36 to 10.64 hours
C) 7.80 to 10.20 hours
D) 8.61 to 9.39 hours