$(8-$point$)$ Five years later Pam and Tom noticed that interest rates for comparable

mortgages have fallen to $4\mathrm{.}75\%.$ Assuming Pam and Tom have made all their payments

on time, $1)$ what is the outstanding mortgage balance that could be refinanced after $60$

payments? Assuming they could get a $4\mathrm{.}75\%,30-$year mortgage, $2)$ what would their

new monthly payment be$?3)$ What would their new payment be if they chose a $25-$year

mortgage? $4)$ A $15-$year mortgage?