6. Steve is repaying a loan with payments of $2,500 at the end of every two years. If the amount of interest in the fourth installment is $2,458, find the amount of principal in the seventh installment. Assume an annual effective interest rate of 13%. (Hint: Use the 2-year effective interest rate to set up an equation for Iq. Solve this equation for n and use it to compute P.,.) a)