public class StdDevHelper
{
	public static double mean(double [] list)
	{
		double sum;
		double mean;
		
		sum = 0;
		mean = 0;
		if (list != null && list.length > 0)
		{
			for (int ii = 0; ii < list.length; ii++)
			{
				sum = sum + list[ii];
			}
			mean = sum / list.length;
		}
		return mean;
	}

	public static double stdDev(double [] list)
	{
		double mean;
		double stdDev;
		double sum;
		
		mean = mean(list);
		stdDev = 0;
		sum = 0;
		
		if (list != null && list.length > 0)
		{
			for (int ii = 0; ii < list.length; ii++)
	      {
	         sum = sum + Math.pow((list[ii] - mean), 2);
	      }
	      stdDev = Math.sqrt(sum / (list.length ));
		}
		return stdDev;
	}
	public static int[] makeArray()
	{
		double mean;
		double [] array1;
		
		array1 = new array[0];
		mean = mean (array1);
		
		return mean;
	}
}