15 years ago, Laura borrowed $424,000 to buy a house. She has a 30 year, 5.4% fixed rate mortgage. She made the 180th payment today. Payments are made monthly. Given that she can refinance at 2.4% p.a. with 15 year maturity, what is the new monthly payment? 1941.85 1841.85 1741.85 1641.85 1541.85