With individual lines at the checkouts, a store manager finds that the standard deviation for the waiting times on Monday mornings is 5.2 minutes. After switching to a single waiting line, he finds that...

With individual lines at the checkouts, a store manager finds that the standard deviation for the waiting times on Monday mornings is 5.2 minutes. After switching to a single waiting line, he finds that for a random sample of 29 customers, the waiting times have a standard deviation of 4.3 minutes. Assume that line waiting times on Mondays are normally distributed. Use a 0.05 significance level to test whether the standard deviation of the waiting times using a single line differs from 5.2 minutes.