Based on Exhibit $7-7,$ what would be the monthly mortgage payments for each of the following situations? $($Round your answers to $2$ decimal places.$)$

$\backslash$table$[[$a$.A$$$156,500,30-$year loan at $7\mathrm{.}5$ percent.,$],[$b$.A$$$214,500,15-$year loan at $6$ percent.,$],[$c$.A$$$195,000,15-$year loan at $7\mathrm{.}5$ percent.,$]]$