Question

Please advise-Thank you.
The Center for Urban Transportation research released a report stating that the average commuting distance in the United States is 10.9 miles Suppose that this average is actually the mean of a sample of 300 commuters and that the sample deviation was 6.2 mi. Estimate the true mean commuting distance using a 99% confidence interval.

Answer 1

Formula using 99% confidence interval:

CI99 = mean ± (2.58)(sd/√n)

Note: ± 2.58 represents 99% confidence interval.

mean = 10.9
sd = 6.2
n = 300

Plug the values into the formula and calculate.

I hope this will help get you started.

Answer 2

I worked it out using + 10.9 =11.82352949 and 10.9 (-) =9.9764501 but how do I word my answer? What does this mean?

Answer 3

This is indicating that there is a 99% chance that the population mean is somewhere within this range (9.98-11.82).

Answer 4

Thanks Much!