Problem 41BSC

The Empirical Rule Based on Data Set 1, blood platelet counts of women have a bell-shaped distribution with a mean of 280 and a standard deviation of 65. (All units are 1000 cells/µL.) Using the empirical rule, what is the approximate percentage of women with platelet counts

a. within 2 standard deviations of the mean, or between 150 and 410?

b. between 215 and 345?

Solution 41BSC

(a)

By using the empirical rule, 95% of all values are within 2 standard deviations of mean are

and

Therefore, about 95% of blood platelet counts of women between 150 and 410.

(b)

By using the empirical rule, 68% of all values are within 1 standard deviation of mean are

and

Therefore, about 68% of blood platelet counts of women between 215 and 345.