As the district's human resources specialist, you have been asked to analyze data on the ages of special education teachers in the district. For a sample of 10 you find them to be as follows: 24, 25, 28, 28, 31, 36, 39, 40, 53, 54. a. Calculate the mean, standard deviation, and range. b. If a new teacher with age 30 is added, what happens to the standard deviation? c. What happens to the range?