Problem 4 (40 points): You just took out a S110 000 mortgage for piece of lake-front land in northern Alberta. You negotiated with your bank for a 9.5% nominal interest rate (compounded monthly) and a 20-year amortization period (the duration over which the loan is calculated to be repaid). (a) What are your monthly payments? (b) A short time later, you're interested in refinancing your mortgage. How much do you still owe after three vears