//Rextester.Program.Main is the entry point for your code. Don't change it.

//Compiler version 4.0.30319.17929 for Microsoft (R) .NET Framework 4.5

​

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text.RegularExpressions;

​

namespace Rextester

{

    public class Program

    {

        private const double N = 10;

        public static void Main(string[] args)

        {

            var inputs = new List<double>{1000.0f, 1.0f, 1.0f, 1000.0f, 1.0f, 1.0f, 1000.0f, 1.0f, 1.0f, 1.0f, 1.0f};

            double average = 1;

            foreach ( var i in inputs )

            {

                var average2 = approxRollingAverage(average, i);

                average = average2;

                Console.WriteLine(i);

            }

            Console.WriteLine(average);

        }

        static double approxRollingAverage (double avg, double input)

        {

            avg -= (avg/N);

            avg += (input/N);

            return avg;

        }

    }

}