The data table contains waiting times of customers at abank, where customers enter a single waiting line that feeds three teller windows. Test the claim that the standard deviation of waiting times is less than 2.1 minutes, which is the standard deviation of waiting times at the same bank when separate waiting lines are used at each teller window. Use a significance level of 0.01. Complete parts(a) through(d) below.

Customers Waiting Times (in minutes)

7.9, 7.4, 7.2, 6.5, 7.4, 6.5, 6.2, 6.9, 7.5, 7.8, 6.9, 7.5, 11.2, 6.2, 7.2, 6.6, 6.5, 7.6, 6.8, 7.6, 6.8, 8.3, 6.2, 9.8, 6.2, 7.8, 7.4, 6.6, 7.7, 6.3, 12.2, 7.1, 6.3, 7.1, 12.6, 7.3, 7.5, 7.6, 7.4, 6.8, 8.8, 8.1, 7.1, 6.5, 7.4, 6.1, 7.8, 6.1, 7.9, 6.7, 4.2, 6.3, 6.9, 8.6, 6.3, 6.5, 6.7, 7.4, 7.6, 7.6

Please help me? Any explanation/detail would be greatly appreciated. If you are able to use StatCrunch to show me that would be even better.