Hey there!
There's multiple ways to express this problem, but I like to do ratios, so we'll go with that. If you prefer fractions, the first number of a ratio is the same as the numerator of a fraction and the second number is the same as the denominator.
The ratio of this problem is 4:448. This basically means there will be 448 miles per 4 inches. This ratio can be simplified by dividing by 4 to make it 1:112. Applying the same logic, there are 112 miles per inch.
112 miles per 1 inch should be your answer. Hope this helped you out! :-)