A publisher wants to estimate the mean length of time (in minutes) all adults spend reading newspapers. To determine this estimate, the publisher takes a random sample of 15 people and obtains the results below. From past studies, the publisher assumes is 2.2 minutes and that the population of times is normally distributed.

9 12 12 8 12 12 6 11 10 11 7 10 10 7 10

Construct the90% and99% confidence intervals for the population mean. Which interval iswider? Ifconvenient, use technology to construct the confidence intervals.

The 90% confidence interval is:

The 99% confidence interval is: