A cylindrical container is used to ship a present. The container has the dimensions of a 12 inch diameter and a height of 18 inches. The present consists of three crystal balls in the shapes of perfect spheres of equal size. The spheres fit perfectly in the container with no additional space between each ball or each ball and the sides of the container. To protect the crystal balls, the package contains Styrofoam peanuts in the empty space. How many cubic inches are occupied by Styrofoam peanuts?
