Question

The blood platelet counts of a group of women have a bell-shaped distribution with a mean of 257.62 and a standard deviation of 62.1 (All units are 1000 cells/muμ L.)

Using the empirical rule, find each approximate percentage below.

	What is the approximate percentage of women with platelet counts within 1 standard deviation of the mean, or between 195.5 and 319.7 ?
	What is the approximate percentage of women with platelet counts between 71.3 and 443.9 ?

a. Approximately 68 % of women in this group have platelet counts within 1 standard deviation of the mean, or between 195.5 and 319.7.

(Type an integer or a decimal. Do not round.)

Approximately ____ % of women in this group have platelet counts between 71.3 and 443.9.

(Type an integer or a decimal. Do not round.)

Answer 1

Given that,

Mean = 257.62

Standard deviation = 62.1

First find,

and  

and  

and

a) From Empirical Rule i) Approximately 68 % of women in this group have platelet counts within 1 standard deviation of the mean, or between 195.5 and 319.7

b) From Empirical Rule iii) approximately 99.7% of women in this group have platelet counts between 71.3 and 443.9