Answer:
The radius is 4.5 ft
Step-by-step explanation:
The volume of a sphere is
V = 4/3 pi r^3
121.5 pi = 4/3 pi r^3
Divide each side by pi
121.5 = 4/3 r^3
Multiply each side by 3/4
121.5 *3/4 = r^3
91.125 = r^3
Take the cube root on each side
(91.125) ^(1/3)= (r^3)^(1/3)
4.5 = r
The radius is 4.5 ft
