Answer:
(∛3)/2 ft = r
Explanation:
Start with the formula for the volume of a sphere: V = (4/3)πr³. Solve this for r³ and then take the cube root of the result:
3V
V = (4/3)πr³ => (3/4)V = πr³ => (------- = r³
4π
3 · 4/81π ft^3 3 · 4π ft³ 3 ft³
Here we have r³ = -------------------- = ---------------- = -------------
4π 8(4π) 8
and so the radius is r = ∛[ (3/8) ft³] = (∛3)/2 ft = r