4. Using the following data set, answer the questions below. 17.5 15.0 13.4 23.9 25.2 19.5 25.8 30.0 22.5 35.3 39.5 23.5 26.5 21.3 22.3 21.6 27.2 21.1 24.0 23.5 32.5 32.2 24.2 35.7 28.0 24.0 16.8 21.1 19.0 30.7 30.2 33.7 19.7 19.7 25.1 27.9 28.5 22.7 31.0 28.4 31.2 24.6 30.2 16.8 26.9 23.3 21.5 18.8 21.4 20.7 a. What are the mean and standard deviation of the data set? b. Construct a centered relative frequency histogram of the data using seven intervals and discuss whether it appears to be a normal data set. C. Evaluate the 95% interval for this data set.