math
posted by cynthia on .
a spherical ball requires approximately 900cm2 of material in order to make it. Find the volume of the ball : The volume is 2579.325cm3
NOW
The ball is sold in a rectangular prism shaped box. What percentage of the volume of the box is taken up by the ball?
Please help me =)

You evidently found r from the area using
4 pi r^2 = area = 900
then
volume = (4/3) pi r^3 = (4 pi r^2) (r/3)
= 900 * (r/3)
now
the volume of the box is (2r)^3 if the sphere just fits in the cube
so the percentage= 100 * (volume of sphere/(2r)^3) 
100 * (4 pi r^3 /24 r^3)
= 400 pi/24 = 52.4 %