Expert: Lynn Houston - 12/3/2009

Question
Question: A sphere has a volume of 85.3Pi* cm cubed. What is the volume of a sphere with a radius that is 3 times longer?

What I know: I know I need to figure out the radius of that sphere that's volume was given, I just don't know how to. I looked through a couple websites for examples but I lost them at certain points because they weren't showing all the steps that led them to each answer.

Please Help?

Answer
Use the equation for the volume of a sphere, V = 4pir^3/3, and solve for r.
So, 85.3pi= 4pir^3/3.  Multiply both sides by 3
255.9pi = 4pir^3   divide by 4pi
63.975 = r^3  take the cube root
r = 3.999  multiply times 3
new radius = 11.997  put this back into the volume equation, V = 4pir^3/3, and solve for V.