Answer
68 ft is the length of the real box car.
Work Step by Step
Let's assume the x is length of the real boxcar .
Now, we will write the proportion for the given details
$\frac{1 inch }{16 ft} = \frac{4.25 inch}{x ft}$
so. $ 1\times x= 4.25\times 16$ (cross multiply)
$ x = 68$
68 ft is the length of the real box car.
