Question

among american women aged 20 to 29 years, 10% are less than 60.8 inches tall, 80% are between 60.8 and 67.6 inches tall, and 10% are more than 67.6 inches tall.17 assuming that the height distribution can ade- quately be approximated by a normal curve, find the mean and standard deviation of the distribution

Answer 1

• mean height is approximately 64.2

• standard deviation is approximately 3.4 inches

Explanation:

Since the distribution is approximately normal, we can use the empirical rule to estimate the mean and standard deviation.

According to the empirical rule:

Approximately 68% of the data falls within 1 standard deviation of the mean

Approximately 95% of the data falls within 2 standard deviations of the mean

Approximately 99.7% of the data falls within 3 standard deviations of the mean

From the information given in the problem, we know that:

10% of women are less than 60.8 inches tall

10% of women are more than 67.6 inches tall

So, we can estimate the mean height as the midpoint between 60.8 and 67.6:

mean = (60.8 + 67.6) / 2 = 64.2 inches

We also know that 80% of women are between 60.8 and 67.6 inches tall. Since this is approximately 1 standard deviation from the mean (on either side), we can estimate the standard deviation as:

standard deviation = (67.6 - 64.2) / 1 = 3.4 inches

Therefore, the mean height is approximately 64.2 inches and the standard deviation is approximately 3.4 inches.