Question: A May 8, 2008, report on National Public Radio (www.npr.org) noted that the average age of firsttime mothers in the United States is slightly higher than 25 years. Suppose that a random sample of 60 first-time mothers taken recently produced an average age of 25.9 years and a standard deviation of 3.2 years. Calculate a 90% confidence interval for the average age of all current first-time mothers.