Mortgage calculation

[frctl]

A family has a $80,000, 20-year mortgage at 8% compounded monthly.
(A)Find the monthly payment
A = 80000, r = 0.08, 12 x 20 = 240

PMT = I get the wrong answer
(should be 669.15)

 

[Cubist]

Your formula seems correct. Maybe you're just typing it into your calculator wrong? The following works in a spreadsheet:-

=80000 * (0.08/12) / (1 - (1 + 0.08/12)^-240)
≈669.15

 

[frctl]

Thank you