A survey of 200 middle managers showed a distribution of the number of hours of exercise they participated in per week with a mean of 3.48 hours and a standard deviation of 4.76 hours. Complete parts (a) through (c) below. a) According to the Normal model, what percent of managers will exercise fewer than one standard deviation below the mean number of hours? D% (Round to the nearest whole number as needed.) b) For these data, what does that mean? Explain. Select the correct choice below and fill in the answer box(es) within your choice. (Type integers or decimals.) O A. One standard deviation below the mean is hours. This means that % of managers are exercising no more than this number of hours. O B. One standard deviation below the mean is hours. This means that % of managers are exercising exactly this number of hours. O C. One standard deviation below the mean is hours, which is impossible. O D. One standard deviation below the mean is hours. This means that % of managers are exercising no fewer than this number of hours. c) Explain the problem in using the Normal model for these data. Choose the correct answer below. O A. The distribution is exponential. O B. The distribution is strongly skewed to the right, not symmetric. OC. The distribution is strongly skewed to the left, not symmetric. O D. The distribution is uniform.