Final answer:
To find the volume of the box, multiply its length, width, and height. The volume is 10.5 cubic feet (option A).
Step-by-step explanation:
To find the volume of a rectangular box, you multiply its length, width, and height. In this case, the length is 3 1/2 ft, the width is 1 1/3 ft, and the height is 2 1/4 ft. First, convert all the fractions to decimals: 3 1/2 ft = 3.5 ft, 1 1/3 ft = 1.33 ft, and 2 1/4 ft = 2.25 ft. Then, multiply the three numbers together: 3.5 ft x 1.33 ft x 2.25 ft = 10.5 cubic feet. Therefore, the volume of the box is 10.5 cubic feet (option A).