A while ago, a couple purchased a home with a sales price of $790,000, making a 10% down payment and financing the rest with a 30-year adjustable rate mortgage fixed at 3.6% for the first six years. Now that the fixed rate period is up, the couple is facing a higher adjustable rate. They now plan to refinance into a fixed rate 15-year mortgage at 4.6%, allowing them to pay it off before they retire. What will their new monthly payments be? Assume there are no costs associated with the refinance.