Question

What is the volume of a sphere with an 18 inch diameter ?

Answer 1

18 inch diameter = 9 inch radius
Sphere Volume   =   4/3 • π • r³
Sphere Volume   =   4/3 * PI * 9^3
Sphere Volume   =   4/3 * PI * 729
Sphere Volume   =   3,053.628

Answer 2

Volume = 3,052.08 in³

Work is attached in the image provided.