A variable-rate mortgage of $142,000 is amortized over 15 years by equal monthly payments. After 18 months the original interest rate of 8% compounded semi-annually was raised to 8.4% compounded semi-annually. Two years after the mortgage was taken out, it was renewed at the request of the mortgagor at a fixed rate of 8.2% compounded semi-annually for a four-year term.

(a) Calculate the mortgage balance after 18 months.

(b) Compute the size of the new monthly payment at the 8.4% rate of interest.

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

(a) The mortgage balance is $___ after 18 months.

(b) The size of the new monthly payment is $___.

(c) The mortgage balance is $___.