C Program to Calculate Average of N Numbers Using Array

Introduction

Calculating the average of numbers is a fundamental programming task. In C, using an array to store the numbers makes the solution more efficient and organized. This approach is particularly useful when dealing with a large number of values.

The average (or arithmetic mean) is calculated by summing all the numbers and dividing by the count of numbers. This program will demonstrate how to implement this calculation in C using array operations.

Formula

In C, we'll implement this by:

1. Declaring an array to store the numbers
2. Reading N numbers from the user
3. Calculating the sum of all elements
4. Dividing the sum by N to get the average

Implementation

Here's a step-by-step implementation of the C program:

1. Include necessary headers (stdio.h for input/output)
2. Declare main function
3. Declare variables for array size and sum
4. Create an array to store numbers
5. Prompt user for number of elements
6. Read each number and store in array
7. Calculate sum of all elements
8. Calculate average by dividing sum by number of elements
9. Display the result

#include <stdio.h>

int main() {
    int n, i;
    float sum = 0, average;

    printf("Enter the number of elements: ");
    scanf("%d", &n);

    float numbers[n];

    for(i = 0; i < n; i++) {
        printf("Enter number %d: ", i+1);
        scanf("%f", &numbers[i]);
        sum += numbers[i];
    }

    average = sum / n;

    printf("Average = %.2f", average);

    return 0;
}

Example

Let's walk through an example with 5 numbers: 10, 20, 30, 40, 50.

1. User enters 5 as the number of elements
2. Program prompts for each number and stores them in the array
3. Sum calculation: 10 + 20 + 30 + 40 + 50 = 150
4. Average calculation: 150 / 5 = 30
5. Program displays "Average = 30.00"