Recent General Social Surveys asked subjects, "How long have you lived in the city, town, or community where you live now?" The possible responses were (less than one year, 1, 2, 3, 4, ...). The responses of 1415 subjects had a mode of "less than one year," a median of 16 years, a mean of 20.3 years and a standard deviation of 18.2 years. b) Based on your answer in (a), is it valid to construct a 99% confidence interval for the true mean for the population represented by this sample? If not, explain why not. If it is valid, do so and interpret normal.