The blood platelet counts of a group of women have a bell-shaped distribution with a mean of 256.3 and a standard deviation of 65.4. (All units are 1000 cells/muL.) Using the empirical rule, find each approximate percentage below. a. What is the approximate percentage of women with platelet counts within 2 standard deviations of the mean, or between 125.5 and 387.1? b. What is the approximate percentage of women with platelet counts between 190.9 and 321.7?