The local computer store has the following ad placed at their doorstep: We do not ensnare our customers into confusing interest rates. We just divide your total cost into 13 and you pay that amount each month for the next 15 months the first payment is due a month from the date of purchase Find the (rather outrageous) effective annual rate that the store's customers are paying when financing their purchase by using the store policy. Hint 15/0.0185 12.995 and 1510.018413.004