Convert the mixed number to inches. 3 feet 8 inches = 44 inches (12 inches per foot x 3 feet= 36 inches + 8 inches= 44 inches). 44 inches (length each section needs to be) x 4 (number of sections needed)=176 inches (total molding needed). To determine the amount of molding needed in feet, convert 176 inches into feet by dividing 176 inches by 12 inches. You get 14 2/3 feet, so the shortest board length is 15 feet.
Take a picture of the graph then re- upload the question with the same words from this one. without it i cannot solve the problem and the whole math equation relies on that graph which isn't here