Respuesta :

68 miles to 42.5's percent of decrease is: 37.5%
Using proportions. 68 miles - 42.5 = 25.5

25.5 x
------ = -----
68 100

Cross multiply:
25.5 x 100 = 2550
68 multiply x = 68x
2550 divided by 68 = 37.5
x = 37.5%