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## In a random sample of 20 people, the mean commute time to work was 31.4 minutes and the standard deviation was 7.1 minutes

In a random sample of 20 people, the mean commute time to work was 31.4 minutes and the standard deviation was 7.1 minutes. Assume the population is normally distributed and use a t-distribution to construct a 80% confidence interval for the population mean u.

What is the margin of error of u? Interpret the results.

The confidence interval for the population mean u is ( , ) (Round to one decimal place as needed.)

The margin of error for u is __. (Round to one decimal place as needed.)

Interpret the results.

A. If a large sample of people are taken approximately 80% of them will have commute times between the bounds of the confidence interval.

B. With 80% confidence, it can be said that the commute time is between the bounds of the confidence interval.

C. With 80% confidence, it can be said that the population mean commute time is between the bounds of the confidence interval.

D. It can be said that 80% of people have a commute time between the bounds of the confidence interval.