==========================================
Work Shown:
5/8 = 0.625
1 inch : 600 miles
0.625*(1 inch) : 0.625*(600 miles)
0.625 inches : 375 miles
--------
An alternative way to solve is like this
(1 inch)/(600 miles) = (0.625 inches)/(x miles)
1/600 = 0.625/x
1*x = 600*0.625
x = 375