1. Joe negotiates a $50, 000 mortgage on a house with semiannual payments of $3, 000 for the first year, $3, 500 for the second year, $4, 000 for the third year, increasing similarly until the final payment. The first payment is due 6 months after the loan. The annual effective interest rate is 10%. Find the outstanding balance to the nearest $500 immediately after the 4th payment.