 
   Formula
 
-      σ = sqrt( Σ(x - m) / n )
+      σ = sqrt( Σ( (x - m)^2 ) / n )
 
   Where:
 


  Formula

      s = sqrt( Σ(x - m) / (n - 1) )

  Where:


  
  /**
  
  Computes variance.
  
  http://en.wikipedia.org/wiki/Variance
  
