volume of a sphere

Question

What is the radius of a hemisphere with a volume of 86784 cm3, to the nearest tenth of a centimeter ?

Answer 1

Volume = (4/3)pi(r^3) = 86784 x 2 (multiply by 2 since it's a hemisphere, not a sphere)

r^3 = (2)86784(3/4)/3.14 = 204376.32 x 2 = 408752,64

r = cube root of 408752.64 cm= about 74.214 cm = radius