Answer:
a) Approximately 95% of healthy women in this group have blood platelet counts between 109.1 and 381.9 (1000 cells/μL).
b) Approximately 99.7% of healthy women in this group have blood platelet counts between 40.9 and 450.1 (1000 cells/μL).
Explanation:
Empirical Rule
The Empirical Rule (also known is the "68-95-99.7" rule) states that nearly all of the data within a normal distribution will fall within three standard deviations of the mean.
- Approximately 68% of the data will fall within one standard deviation of the mean.
- Approximately 95% of the data will fall within two standard deviations of the mean.
- Approximately 99.7% of the data will fall within three standard deviations of the mean.
Given the blood platelet count of a group of women has a bell-shaped distribution with:
- Mean μ = 245.5 (1000 cells/μL)
- Standard deviation σ = 68.2 (1000 cells/μL)
To determine the lower and upper bounds for blood platelet counts for 95% of the women, subtract and add two standard deviations to the mean:

Therefore, approximately 95% of healthy women in this group have blood platelet counts between 109.1 and 381.9 (1000 cells/μL).
To determine the lower and upper bounds for blood platelet counts for 99.7% of the women, subtract and add three standard deviations to the mean:

Therefore, approximately 99.7% of healthy women in this group have blood platelet counts between 40.9 and 450.1 (1000 cells/μL).