The prices of all college textbooks follow a bell-shaped distribution with a mean of $108 and a standard deviation of $15. Using the empirical rule, nd the interval that contains the prices of 99.? 9'5 of college textbooks. eTextbook and Media Hint Assistance Used Empirical rule Fora bellshaped distribution, approximately 1. 68 % of the observations lie within one standard deviation of the mean. 2. 95 3'}: of the observations lie within two standard deviations of the mean. 3. 99.7 '36 of the observations lie within three standard deviations of the mean