Question

In order to estimate the average time spent on the computer terminals per student at a local university, data were collected from a sample of 81 business students over a one-week period. Assume the population standard deviation is 1.2 hours. If the sample mean is 9 hours, then the 95% confidence interval is approximately

a. The 95% interval because it is a less accurate interval. The 95% interval because it is a less accurate interval.

b. The 99% interval because it is a more useful interval.

c. The 95% interval since, in order to decrease the confidence from the 99% to 95%, the margin of error should increase so that the intervals constructed using sampling will capture the true mean more often.

d. The 99% interval since, in order to increase the confidence from the 95% to 99%, the margin of error should increase so that the intervals constructed using sampling will capture the true mean more often.

Answer 1