A department store accepts three types of charge cards: MasterCard, Visa, and their store card. Charges are normally distributed. A random sample of 18 card purchases included 6 MasterCard, 7 Visa, and 5 store charges.The total sum of squares calculated (SStotal) at 7,114, and the sum of squares error (SSE) was 3776.0333. At the .05 sigificance level, can we conclude there is a difference in the mean amounts chrged per purchase on the three cards? Assume normal distribution is present.