YAnswer on excel with functions and formula text please. You bought your house $7$ years and $4$ months ago. To finance the purchase, you took out a $15-$year fixed$-$rate mortage to borrow $$400,000$ at an interest rate of $7\mathrm{.}2\%($APR$).$ You just made a mortgage payment and now want to refinance the mortgage. How much do you owe on your existing mortgage?