C :

#include <stdio.h>

int main(void) {
	int i, n;
	double x, s = 0;
	scanf("%d", &n);
	for(i = 1; i <= n; i ++, s += x)
		scanf("%lf", &x);
	printf("%.2lf", s / n);
	return 0;
}

C++ :

#include<cstdio>
using namespace std;
int main()
{
	int i,n;
	double a,s=0;
	scanf("%d",&n);
	for(i=1;i<=n;i++)
	{
		scanf("%lf",&a);
		s=s+a;
	}
	printf("%.2lf",s/n);
	return 0;
}

Pascal :

var n,i:longint;
    s,a:real;
begin
  s:=0;
  readln(n);
  for i:=1 to n do
    begin
      read(a);
      s:=s+a;
    end;
  s:=s/n;
  writeln(s:0:2);
end.