Consider the lengths of alligators to be { 18.7, 12.3, 18.6, 16.4, 15.7, 18.3, 15.8, 14.9, 17.6, 16.4, 16.7, 17.8, 16.2, 13.8, 15.2, 14.7, 13.2, 15.8, 14.6, 16.6, 16.2, 18.1, 17.5, 17.3 }. According to the Empirical Rule, 68% of the data should fall between what two numbers?