The volume of a sphere is found by this formula V = (4/3)*pi*r^3
We are given the volume is V = 972pi and we need to find r
Plug in that value for V and solve for r V = (4/3)*pi*r^3 972pi = (4/3)*pi*r^3 972 = (4/3)*r^3 ... the pi's cancel out (divide both sides by pi) 3*972 = 4r^3 ... multiply both sides by 3 2916 = 4r^3 4r^3 = 2916 r^3 = 2916/4 ... divide both sides by 4 r^3 = 729 r = (729)^(1/3) ... apply the cube root to both sides r = 9
The radius is 9, so the diameter is d = 2*r = 2*9 = 18 cm
