Anyone kurt is financing a $315,000 mortgage for 30 years at a fixed rate of 7.35%. what is the total cost of the principal and interest after 30 years? $651,078.00 $676,305.00 $781,293.60 $788,489.94

Loan Cost Total = (r * p * n) / [1 -(1 +r)-n]
See attached graphic
rate gets divided by 1,200 = 0.006125
n = number of payments = 30 * 12 = 360

Loan Cost Total = (.006125 * 315,000 * 360) / [1 - (1.006125)^-360]
Loan Cost Total = ( 694,575 ) / [1 - ( 0.1109944992 )
Loan Cost Total = 694,575 / 0.8890055008
Loan Cost Total = 781,294.38

Considering all the rounding in the calculations, it seems that answer "C" 781,293.60 is really close.  (78 cents lower than what I calculated).

Source:
http://www.1728.org/loanfrm4.htm

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