There are three-month interest rates for credit card installment: 0.75%( 10 or above), 0.80%(6 installments) and 0.95%(3 installments). Sometimes there are discounts, and the corresponding annual interest rates are 9%, 9.6%, 1 1.4%, which are calculated and available in the market. According to your calculation, the total interest is 199.96, the annual interest rate is 199.96/5288=3.78%, and the monthly interest rate is 3.78%/ 12=0.32%.

This algorithm is based on the decreasing of your principal. In the first month, your principal is 5288, and in the second month, it is 4847. It will be reduced every month, and the interest you need to pay every month is 16.7 yuan.

The interest of the nth month is (5288-44 1n)x%, which constitutes arithmetic progression.

Find the sum of arithmetic series,12/2 (5288-441) x% =16.7, and the annual yield is greater than 5.74%.