Suppose Bank of America developed a credit card promotion to entice its customers to increase the balances on their credit cards. To test the effectiveness of different ways of communicating this promotion, Bank of America sent the promotion to some customers through e mail, sent it to other customers through traditional mail, and did not send it to other customers. A random sample of customers from each group was selected, and their credit card balances following the promotion period were recorded. These data can be found in the file credit card promotion. xlsx.

a. Perform a one way ANOVA using α = 0.05 to determine if there is a difference in the average credit card balances of these three groups.

b. If warranted, perform a multiple comparison test to determine which pairs are different using α = 0.05.

c. What conclusions can be drawn about the effectiveness of communicating the promotion?

d. Verify your results with Excel and PHStat².