At one University, the mean distance commuted to campus by students is 17.0 miles, with a standard deviation of 4.1 miles. Suppose that the commute distances are normally distributed and complete the statements: a: approximately ___% of the students have commute distances o between 12.9 miles and 21.1 miles, and b: Approximately 95% of students have commute distances between ___ miles and ___ miles