382 cubic inches of it.
One foot
volume of a sphere (the ball) = 4/3*pi*radius3 volume of box - volume of sphere = space remaining 27 - 4/3*pi*1.53 = 12.86283306 space remaining is about 13 cubic inches
One square inch
One
4 square feet are needed
155520 sq inch
It is not exactly the same, but it is very similar. A space hopper has handles, and a regular rubber ball does not. A space hopper is also much larger than a normal rubber ball.
It depends on the size of the fountain. You have to calculate the height, depth, and width to figure out how much space is needed.
54in
All of it.
30'
1 half of a inch