Lenders primarily use the Fair Isaac Corporation (FICO) model to determine credit scores. FICO grades consumers on a 300- to 850-point range; a higher score indicates less risk to the lender. A score of 800 or higher is considered exceptional; 740 to 799 is very good; 670 to 739 is good; 580 to 669 is fair; and 579 or lower is poor. According to MyFICO.com your credit score can impact interest rates available to you as follows: FICO score APR 760-850 4.17% 700-759 4.392% 680-699 4.569% 660-679 4.783% 640-659 5.213% 620-639 5.759% a) Using the loan rate available to someone with a FICO credit score of 750, calculate the monthly payment and total paid over the life of a $250,000 30-year fixed-rate mortgage for someone with this credit score. b) Now, calculate the monthly payment and total paid using the loan rate available to someone with a FICO credit score of 650. c) Calculate the difference in monthly payment and the total interest paid for someone with a very good credit rating (750) with someone who has a low credit rating (650).