Question

The systolic blood pressure of 18- year- old women is normally distributed with a mean of 120 mmHg and a standard deviation of 12 mmHg. What percentage of 18- year- old women have a systolic blood pressure that lies within 3 standard deviations to either side of the mean?

Answer 1

99.74%

Explanation:

Using empirical rule (68 - 95 - 99.7)

Approximately, 99.7% data falls in 3 standard deviation of the mean.

Answer 2

Answer: 99.7% of of 18- year- old women have a systolic blood pressure that lies within 3 standard deviations to either side of the mean

Explanation:

We would apply the standard deviation rule. The Standard Deviation Rule states that for a normal distribution, nearly all of the data will fall within three standard deviations of the mean . The empirical rule is further illustrated below

68% of data falls within the first standard deviation from the mean.

95% fall within two standard deviations.

99.7% fall within three standard deviations.

From the information given, the mean is 120 mmHg and the standard deviation is 12 mmHg.

Therefore,

99.7% of of 18- year- old women have a systolic blood pressure that lies within 3 standard deviations to either side of the mean.