The following data represents the ages of 21 students in a class: 22, 24, 19, 17, 20, 27, 24, 23, 26, 17, 19, 22, 25, 21, 21, 22, 22, 21, 21, 20, 22.
a. Determine the skewness of the data
b. Determine the kurtosis of the data
c. Determine the excess kurtosis.