In a study of pulse rates of men, a simple random sample of 142 men results in a standard deviation of 11.0 beats per minute. The normal range of pulse rates of adults is typically given as 60 to 100 beats per minute. If the range rule of thumb is applied to that normal range, the result is a standard deviation of 10 beats per minute. Use the sample results with a 0.10 significance level to test the claim that pulse rates of men have a standard deviation equal to 10 beats per minute; see the accompanying StatCrunch display for this test. What do the results indicate about the effectiveness of using the range rule of thumb with the "normal range" from 60 to 100 beats per minute for estimating sigma in this case? Assume that the simple random sample is selected from a normally distributed population.

Let sigma denote population standard deviation of the pulse rates of men (in beats per minute). Identify the null and alternative hypothesis.