Do you have 4 specific points?
there might be a better way but i would try to do it as a locus question.
the distance between 2 three dimensional points is
sqrt[ (x 2-x 1) 2 + (y 2-y 1) 2 + (z 2-z 1) 2]
You have got your 4 points plus you can let the centre be
(x c,y c,z c)
So the distance from each of the four points to the centre would have to be equal.
I'd set up the 4 equations and if they looked too difficult to solve myself I'd try to solve them with an online calculator . (to find the centre)
Once you have the centre, you can work out the radius.
Then you can write down the formula of the sphere. (All you need is the centre and the radius)
+118654 
