4.37.-On January 1st, Frank bought a used car for $72,000 and agreed to pay it as follows: ¼ down payment; the balance to be paid in 36 equal monthly payments; the first payment due February 1; an annual interest rate of 9%, compounded monthly.a)What is the amount of Frank’s monthly payment?b)During the summer, Frank made enough money to pay off the entire balance due on the car as of October 1. How much did Frank owe on October 1 (of the initial year)?