C :

#include<stdio.h>
#include<math.h>
int main()
{
	int n;
	scanf("%d",&n);
	float a,b,c;
	scanf("%f%f%f",&a,&b,&c);
	printf("%.2f",(a+b+c)/n);	
}

C++ :

#include<stdio.h>
int main(void)
{
    int n;
    float a;
    float b,c;
    //freopen("1023A3.in","r",stdin);
    //freopen("1023A3.out","w",stdout);
    scanf("%d%f%f%f",&n,&a,&b,&c);
    printf("%.2f\n",(a+b+c)/n);
 
    return 0;
}

Java :

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        float sum = 0;
        for (int i = 0;i<3;i++){
            float a = sc.nextFloat();
            sum+=a;
        }
        System.out.printf("%.2f",sum/n);
    }
}

Python :

# coding=utf-8
#python2
a = int(input())
b,c,d = map(float,raw_input().split())
x = (b+c+d)/a
print('%.2f'%x)

C# :

using System;
using System.Collections.Generic;
using System.Diagnostics.SymbolStore;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp2
{
    internal class Program
    {
        static void Main()
        {
            //int[] days = { 31,28,31,30,31,30,31,31,30,31,30,31};
            int n = Convert.ToInt32 (Console.ReadLine());
            string[] a1 = Console.ReadLine().Split();
            double r = Convert.ToDouble(a1[0]);
            double b = Convert.ToDouble(a1[1]);
            double c = Convert.ToDouble(a1[2]);
            float pi = 3.1415926f;
            string S = ((r + b+c) / n).ToString("0.00");

            Console.WriteLine(S);

            Console.ReadKey();

        }
    }
}