1.A report in USA TODAY stated that the average age of commercial jets in the United States is 14 years. An executive of a large airline company selects a sample of 36 planes and finds the average age of the planes is 11.8 years. The standard deviation of the sample is 2.7 years. At = 0.01, can it be concluded that the average age of the planes in her/his company is less than the national average? (Source: USA TODAY)

a.State the null and alternative hypothesis and identify the claim; (determine whether to conduct a left, right or two-tailed test)

b.Find the critical value(s) at = 0.01

c.Compute the test statistic value;

d.Determine whether you should accept or reject the null.

e.Can it be concluded that the average age of the planes in her/his company is less than the national average