Expert: Soroban - 5/13/2007

Question
How are you supposed to find the radius of a sphere while you know the volume? What  I mean is I'm supposed to find the radius of this sphere with its given volume: 1436.76 cm cubed.
how can I find the radius?  I already have the answer, 7 cm, but I don't know how to figure it out.  

Answer
Hello, sfeb!

You're expected to know this volume formula for a sphere:
   V  =  (4/3)ð r³

We are given the volume; we must solve for r.

   (4/3)ð r³  =  1436.76

Multiply both sides by 3/4ð:
   r³  =  (3/4ð)(1436.76)  =  343.0011841

Take the cube root of both sides:
   r  =  7.000008055

Answer:  r  =  7 cm
.