Problem 4 Ellen borrows 10,000 for 10 years at a 9% effective annual rate. She pays interest yearly and will repay the principal by paying 10 annual payments into a sinking fund. The first interest and sinking fund payments will be made at the end of the first year. Ellen's sinking fund payments will start at 1,000 and will decrease by 100 each year. The 10th payment will include an additional amount. The sinking fund will earn interest at a 7% effective annual rate for the four years following the first payment and will earn interest at an 8% effective annual rate for the last five years. Determine the total amount of Ellen's 10th sinking fund payment