In a random sample of

2525

people, the mean commute time to work was

31.6

minutes and the standard deviation was

7.2

minutes. Assume the population is normally distributed and use a t-distribution to construct a

80%

confidence interval for the population mean

mu.

What is the margin of error of

mu?

Interpret the results.

The confidence interval for the population mean

mu

is left parenthesis nothing comma nothing right parenthesis

(Round to one decimal place as needed.)