The length of part of a model plane is #0.75# inches and the length of the part on the plane is #2# feet. What is the scale factor?
The scale factor is the ratio between the image (or model) and the original shape.
Firstly the units must be the same. In this case I will assume that the model is smaller than the original.
This is quite a common scale for model aeroplanes and tanks.
The real life size is 32 times bigger than the model.