An economics professor randomly selected 100 millionaires in the United States. The average age of these millionaires was 50 years. If the standard deviation of the entire population of millionaires...

 An economics professor randomly selected 100 millionaires in the United States.  The average age of these millionaires was 50 years.  If the standard deviation of the entire population of millionaires is 10 years, find the 95% confidence interval for the mean (μ)age of all United States millionaires