Because the balls or spheres are tightly packed in a cube, their radius is approximately equal to 2 ft. The volume of a sphere is calculated through the equation,
V = 4/3πr³
Substituting the known radius,
V = 4/3π(2 ft)³
V = 33.51 ft³
The 9 spheres will have a total volume of 301/59 ft³ which is also equal to 521152.52 in³.