Question

Use the range rule of thumb to estimate the standard deviations.

HW Score: 17.71%, 1.95 of 11 points
Points: 0.67 of 1
The 155 heights of males from a data set of body measurements vary from a low of 150.0 cm to a high of 191.1 cm. Use the range rule of thumb to estimate the standard deviations and compare
the result to the standard deviation of 10.84 cm calculated using the 155 heights. What does the result suggest about the accuracy of estimates of s found using the range rule of thumb? Assume the
estimate is accurate if it is within 1.4 cm.

Answer 1

Answer: The range rule of thumb is used to estimate the standard deviation by taking the range of the data and dividing it by 4:

s = (max - min) / 4

In this case, the range is 191.1 cm - 150.0 cm = 41.1 cm.

s = 41.1 cm / 4 = 10.275 cm

This estimate of the standard deviation is 10.275 cm, which is close to the actual standard deviation of 10.84 cm. Since the difference between the two is less than 1.4 cm, we can say that the estimate is accurate.