Sum & average of n numbers.

do-while.cpp

#include <iostream>
#include <cmath>
using namespace std;

int main() 

{
    double sum =0, i=0, n , grade=0;  
    cin >> n;                  
    
    do  
    {
        i++;  
        cin >> grade;
  	sum = sum + grade; 
	}

	while(i<=n);

    cout << "Average = "<< sum/n<<endl;
  
	return 0;
}