Only need question b).

5. A study was conducted to estimate the mean commute distance that all employed U.S. adults travel to work. Suppose a random sample of 49 employed U.S. adults gives a mean commute distance of 22 miles and that from prior studies, the population standard deviation is assumed to be 8.4 miles. a Identify each of the following if possible (state N/A if not applicable for this problem): Population Variable Variable Type Sample Size 0 = x - bar = S = p = p - hat = SE = ESE = b) Find the 90%, 95% and 99% Confidence Interval 90% 95% 99%