An engineers union in Columbus, Ohio claims that the average pay for women

An engineers union in Columbus, Ohio claims that the average pay for women working in the auto industry is $16/hr. A simple random sample of 9 women working in 1998 as engineers in the automotive industry in Columbus, Ohio revealed that the average pay rate was $15/ hr with a standard deviation of $2.

(a) Find a 99% confidence interval on the true mean pay rate of women engineers.

(b) What can you say about the union's claim? Write a sentence or two.