Solution and explanation
Present value of the $1,500 monthly payments is
PMT $1,500
Annual Rate 6.05%
Number of period (NPER) 420
Present value Annuity (PVA) (calculated in excel using PV function) $261,528.41
[tex]\mathrm{PVA}=\$ 1,500\left[\left(1-\left\{1 /[1+(.0605 / 12)]^{\wedge} 420\right\}\right) /(.0605 / 12)\right][/tex] $261,528.41
Cost of Home $310,000
Amount of principal still owe = $310,000 - $261,528.41 $48,471.59
Balloon payment in 35 years, which is the FV of the remaining principal =
Present Value $48,471.59
Annual Rate 6.05%
Number of period (NPER) 420
Future Value (calculated in excel using FV function) $400,677.90
Balloon payment = [tex]\mathbf{S} 48,471.59[1+(.0605 / 12)] 420[/tex] $400,677.90