Java Program to Calculate Average of N Numbers

How to Calculate the Average

The average (or arithmetic mean) of a set of numbers is calculated by summing all the numbers and then dividing by the count of numbers. The formula is:

For example, if you have the numbers 5, 10, and 15:

• Sum = 5 + 10 + 15 = 30
• Count = 3
• Average = 30 / 3 = 10

This is the basic formula used in our Java program.

Java Program to Calculate Average

Here's a complete Java program that calculates the average of n numbers entered by the user:

import java.util.Scanner;

public class AverageCalculator {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        System.out.print("Enter the number of elements: ");
        int n = scanner.nextInt();

        double[] numbers = new double[n];
        double sum = 0;

        for (int i = 0; i < n; i++) {
            System.out.print("Enter number " + (i + 1) + ": ");
            numbers[i] = scanner.nextDouble();
            sum += numbers[i];
        }

        double average = sum / n;

        System.out.println("The average is: " + average);

        scanner.close();
    }
}

How the Program Works

1. The program starts by creating a Scanner object to read user input.
2. It prompts the user to enter the number of elements (n).
3. It creates an array to store the numbers and initializes a sum variable to 0.
4. Using a for loop, it prompts the user to enter each number and adds it to the sum.
5. After collecting all numbers, it calculates the average by dividing the sum by n.
6. Finally, it prints the average and closes the scanner.

Example Calculation

Let's walk through an example where we calculate the average of 4 numbers: 12, 15, 18, and 20.

Step-by-Step Calculation

1. Sum = 12 + 15 + 18 + 20 = 65
2. Count = 4
3. Average = 65 / 4 = 16.25

The program would output: "The average is: 16.25"