using System;

public class Program

{

    static private double average(double a,double b, double c, double d)

{ double av = a+b+c+d;

 double four = 4;

 double rage = (av/four);

 return av;

}

    public static void Main()

    {

        Console.WriteLine("Please enter 4 numbers you'd like to find the average of");

        double num1=double.Parse(Console.ReadLine());

        double num2 =double.Parse(Console.ReadLine());

        double num3 =double.Parse(Console.ReadLine());

        double num4 =double.Parse(Console.ReadLine());

        Console.WriteLine("the average of " +num1+num2+num3+num4+ " is"+ average(num1,num2,num3,num4));

    }

}

​