Standard deviation of generic list? [duplicate]

The example above is slightly incorrect and could have a divide by zero error if your population set is 1. The following code is somewhat simpler and gives the “population standard deviation” result. (http://en.wikipedia.org/wiki/Standard_deviation)

using System;
using System.Linq;
using System.Collections.Generic;

public static class Extend
{
    public static double StandardDeviation(this IEnumerable<double> values)
    {
        double avg = values.Average();
        return Math.Sqrt(values.Average(v=>Math.Pow(v-avg,2)));
    }
}