Question

The blood pressure in millimeters was measured for a large sample of people. The average pressure is 140 mm, and the sd of the measurements is 20 mm. The histogram looks reasonably like a normal curve. Use the normal curve to estimate the following percentages. Choose the answer that is closest to being correct. A. 10. 6%b. 89. 4%c. 39. 4%d. 78. 8%e. 68. 27%

Answer 1

(e) 68.27%

Step-by-step explanation:

Since the histogram of the blood pressure measurements looks reasonably like a normal curve and we know the mean and standard deviation, use the properties of the normal distribution to estimate the percentages.

use the empirical rule to estimate the percentage of measurements that fall within a certain range of the mean. According to this rule, about 68% of the measurements fall within one standard deviation of the mean, about 95% fall within two standard deviations of the mean, and about 99.7% fall within three standard deviations of the mean.

To estimate the percentage of measurements that fall between the mean and one standard deviation above it, add the mean and the standard deviation:

140 + 20 = 160

use the empirical rule to estimate that about 68% of the measurements fall between 120 and 160 mm.

Therefore, the answer that is closest to being correct is (e) 68.27%.