8. Black Jack A gambling casino records and plots the mean daily gain or loss from five blackjack tables on an x chart. The overall mean of the sample means and the standard deviation of the combined data over 40 weeks were x 5$10,752 and s5$1605, respectively.

a. Construct an x chart for the mean daily gain per blackjack table.

b. How can this x chart be of value to the manager of the casino?