Calculate Average of N Numbers in C++

How to Calculate the Average

The average (mean) of a set of numbers is calculated using this simple formula:

To calculate the average in C++, you need to:

1. Read the numbers from the user or from an array
2. Sum all the numbers
3. Count how many numbers there are
4. Divide the sum by the count
5. Display the result

C++ Implementation

Here's a complete C++ program that calculates the average of n numbers:

#include <iostream>
#include <iomanip>

using namespace std;

int main() {
    int n;
    double sum = 0.0, average;

    cout << "Enter the number of elements: ";
    cin >> n;

    double numbers[n];

    cout << "Enter " << n << " numbers:" << endl;
    for(int i = 0; i < n; i++) {
        cin >> numbers[i];
        sum += numbers[i];
    }

    average = sum / n;

    cout << fixed << setprecision(2);
    cout << "The average is: " << average << endl;

    return 0;
}

The program:

1. Declares variables for the count of numbers, sum, and average
2. Prompts the user to enter the number of elements
3. Creates an array to store the numbers
4. Uses a loop to read each number and add it to the sum
5. Calculates the average by dividing the sum by the count
6. Displays the result with 2 decimal places

Worked Example

Let's calculate the average of these 5 numbers: 12, 15, 18, 20, 25.

The average of these numbers is 18. You can verify this using the calculator below.