For the new car:
PMT = P * (r/n) / (1 - (1 + r/n)^(-nt))
P = $29,000
r = 5.15% = 0.0515
n = 12 (number of payments per year)
t = 3 years
PMT (new car) = $29,000 * (0.0515/12) / (1 - (1 + 0.0515/12)^(-12*3))
PMT (new car) ≈ $867.53
For the used car:
P = $15,000
r = 6.44% = 0.0644
n = 12
t = 5 years
PMT (used car) = $15,000 * (0.0644/12) / (1 - (1 + 0.0644/12)^(-12*5))
PMT (used car) ≈ $293.60
Therefore, the difference in monthly payments between financing the new car and financing the used car is:
$867.53 - $293.60 = $573.93