Let's see how much a lower mortgage rate might save. Suppose you want to get a $200,000, 30-year mortgage. The monthly payments for different mortgage interest rates are given in the table below and can easily be computed on Excel. Mortgage Interest Rate (APR) 6% 5% 4% Monthly Payment Total cost of mortgage $1,199.10 $1073.64 $954.83 30 x 12 x $1073.64 = $386,510.40 1. Find the total cost of the mortgage over 30 years at a. APR = 4% b. APR = 6%