Suppose that you decide to buy a car for ​$26 comma 635​, including taxes and license fees. You saved $ 8000 for a down payment and can get a four​-year car loan at 6.45​%. Use PMT equals StartStartFraction Upper P left parenthesis StartFraction r Over n EndFraction right parenthesis OverOver left bracket 1 minus left parenthesis 1 plus StartFraction r Over n EndFraction right parenthesis Superscript negative nt right bracket EndEndFraction to find the monthly payment and the total interest for the loan.