For a 4-unit class like Statistics, students should spend average of 12 hours studying for the class. A survey was done on 28 students, and the distribution of total study hours per week is bell-shaped with a mean of 13 hours and a standard deviation of 2.8 hours. Use the Empirical Rule to answer the following questions. hours and hours on Statistics each week. a) 68% of the students spend between C] hours and E hours on Statistics each week. b) 95% of the students spend between c) 99.7% of the students spend between E hours and E hours on Statistics each week