Which of the following proportions could be used to convert 3,600 feet into miles? 3,600 ft / 1 mi = 5,280 ft / x 3,600 ft / 5,280 ft = 1 mi / x
X / 3,600 = 5,280 ft / 1 mi
3,600 ft / x = 5,280 / 1 mi