The interest rate for the first four years of a $37,000 mortgage loan was 4.25% compounded semiannually. The monthly payments computed for a 8-year amortization were rounded to the next higher $10. (Do not round intermediate calculations and round your final answers to 2 decimal places.)

a. Calculate the principal balance at the end of the first term. Principal balance $

b. Upon renewal at 6.75% compounded semiannually, monthly payments were calculated for a four-year amortization and again rounded up to the next $10. What will be the amount of the last payment?