Question

In a random sample of

2626

​people, the mean commute time to work was

30.330.3

minutes and the standard deviation was

7.37.3

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

9595​%

confidence interval for the population mean

muμ.

What is the margin of error of

muμ​?

Interpret the results.

The confidence interval for the population mean

muμ

is left parenthesis nothing comma nothing right parenthesis .,.

​(Round to one decimal place as​ needed.)

The margin of error of

muμ

is

nothing.

​(Round to one decimal place as​ needed.)

Answer 1

Given : Sample size=n=26

Sample mean=

Sample standard deviation=s=7.3

Significance level=

Now , ; From t-table

Therefore , the 95% confidence interval for the population mean is ,

Interpretation : The confidence interval for the population mean is ( 27.4 , 33.2 )

The margin of error is ,