The blood platelet counts of a group of women have a bell-shaped distribution with a mean of 250.6 and a standard deviation of 69.5. (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 3 standard deviations of the mean, or between 42.1 and 459.1? b. what is the approximate percentage of women with platelet counts between 111.6 and 389.6?