12*) Tamara and Roberto are taking out a $250,000 mortgage at 3.5% compounded semi-annually. Roberto wants to pay it off with end of month payments over the standard 25 years. Tamara thinks they will pay it off faster and save interest if they just start making $1,300 end of month payments instead. Determine: (4) a) the size of the monthly payments if paid off over 25 years b) the number of payments that will be needed if the make the $1,300 payments c) the size of the last payment, if the make the $1,300 payments d) the amount of interest that would be saved with the $1,300 payments instead of the payments made over 25 years (in part "a")