You are considering refinancing your home. Under the original terms of your mortgage you borrowed $250,000 to be repaid with equal monthly payments over 30 years. The APR on the loan was 4.5%. You have 20 years of payments remaining. If you now can refinance the remaining loan with no prepayment penalties at a 3.5% APR by how much will your monthly payment drop? What is the present value of your savings if your opportunity cost is represented by an APR of 3.5% (with monthly compounding)?