If we want to use the sample data from Exercise to test the claim that the sample is from a population with a standard deviation less than 1.8 min, we must satisfy the requirements of having a simple random sample and a normally distributed population. In Exercise it was stated that the sample is a simple random sample.

a. In general, how does the normality requirement for a hypothesis test of a claim about a standard deviation differ from the normality requirement for a hypothesis test of a claim about a mean?

b. What methods can be used to determine whether the normality requirement is satisfied?