Avariable-rate mortgage of $148,000 is amortized over 25 years by equal monthly payments. After 18 months the original interest rate of 8% compounded semi-annually was raised to 8.5% compounded semi-annually. Three years after the mortgage was takenout, it was renewed at the request of the mortgagor at a fixed rate of 8.3% compounded semi-annually for afour-year term.

(a) Calculate the mortgage balance after 18 months.

(b) Compute the size of the new monthly payment at the 8.5% rate of interest.

(c) Determine the mortgage balance at the end of thefour-year term.