He blood platelet counts of a group of women have a bell-shaped distribution with a mean of 252.5 and a standard deviation of 65.9 . (All units are 1000 cells/mu L.) Using the empirical rule, find each approximate percentage below. a. What is the approximate percentage of women with platelet counts within 1 standard deviation of the mean, or between 186.6 and 318.4 ? b. What is the approximate percentage of women with platelet counts between 54.8 and 450.2 ?