[Chad]

Now that we have our variance, the last step is extremely easy. We simply take the square root of variance to give us the Standard Deviation value!!!

public double CalculateStandardDev(double listOfDoubles)
{
     int sizeOfList = listOfDoubles.size();
     double temporarySum = 0;

     for(int i=0; i<sizeOfList; i++)
     {
         temporarySum += listOfDoubles[i];
     }

     double averageOfList = temporarySum / sizeOfList;

     for(int j=0; j<sizeOfList; j++)
     {
         listOfDoubles[j] = pow(listOfDoubles[j] - averageOfList, 2);
     }

    double squaredDifference = 0;
    double variance = 0;

    for(int k=0; k<sizeOfList; k++)
   {
         squaredDifference += listOfDoubles[k];
   }

   variance = squaredDifference / sizeOfList;

   double standardDeviationValue = sqrt (variance );
   return standardDeviationValue;
}