The bottom-line figure is amount to be financed=$4,692.58. All the other figures above this are the dealer's own calculations.
The monthly payment must cover this plus interest. 48 payments of $129.05=$6,194.40.
The growth is 6194.4/4692.58=1.32004 approx.
(1+r)^4=1.32004; 4log(1+r)=log1.32004=0.12059, so log(1+r)=0.03015 approx, 1+r=1.0719, making r=7.19% per annum compound interest rate. 4692.58+1501.63=$6,194.21 is the amount estimated by the dealer. The difference can be explaned by rounding errors affecting the cents calculation. Using 6194.21/4692.58=1.32000 still gives 7.19% or 7.2% to the nearest tenth.