Since the scale is 1:83, the real airplane is 83 times longer than the model airplane.
real length = 10.5 in * 83 = 871.5 in
Now we convert 871.5 in into ft.
1 ft = 12 in, so 1 in = 1/12 ft
We divide the number of inches by 12 to find the number of feet.
871.5 in = 871.5/12 ft = 72.625 ft
