Try 4 feet because there are 12 inches in 1 foot. so I divided 47.5 by 12 and got 3.95 and rounded it up to 4

Given: 24 boards that are 47 1/2 inches long. 24 * 47.5 inches = 1,140 inches 1 foot = 12 inches 1,140 inches * 1foot/12 inches = 1140 ft/12 = 95 feet. 95 feet / 24 boards = 3.958 or 4 feet. Each board must measure 4 feet.