The file AirportRating contains the rating of large and medium size airports in the United States and Canada. Source: Data extracted from N. Trejos, “Portland, Indianapolis Top Airport Rankings, USA Today, December 16, 2016, p. 4B. For large and medium airports separately: a. Compute the mean, median, and mode. b. Compute the variance, standard deviation, range, coefficient of variation, and Z scores. c. Are the data skewed? If so, how? d. Based on the results of (a) through (c), what conclusions can you reach about the rating of large and medium size airports?