random sample of the closing stock prices in dollars for a company in a recent year is listed below. Assume that

is $2.33.

Construct the90% and 99%confidence intervals for the population mean. Interpret the results and compare the widths of

the confidence intervals.

18.06	16.56	18.21	22.96	19.88	16.05	16.77	19.41
21.92	21.84	21.98	15.81	21.26	19.26	21.02	19.73

Part 1

The 90% confidence interval is .