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14.4.2 3 Question help A variable-rate mortgage of $141,000 is amortized over 25 years by equal monthly payments. After 12 months the original interest rate of 5% compounded semi-annually was raised to 7.8% 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 5.6% compounded semi-annually for a four-year term. (a) Calculate the mortgage balance after 12 months. (b) Compute the size of the new monthly payment at the 7.8% rate of interest. (c) Determine the mortgage balance at the end of the four-year term