What is Mean in Statistics (Formula, Calculation, Examples & Properties)

Last Updated : 14 Aug, 2024

What is a Mean?

Mean is the average of the given numbers which is calculated by dividing the sum of given numbers by the total count of numbers.

Example:

Find the mean of the given numbers 2, 4, 4, 4, 5, 5, 7, and 9?

Mean of 2, 4, 4, 4, 5, 5, 7, 9
Solution:

Step1: Take sum of all numbers, 2 + 4 + 4 + 4 + 5 + 5 + 7 + 9 = 40
Step2: Divided sum by the total count of numbers, 40/ 8 = 5

Properties of Mean:

The mean (or average) is the most popular and well-known measure of central tendency.
It can be used with both discrete and continuous data, although its use is most often with continuous data.
There are other types of means. Geometric mean, Harmonic mean, and Arithmetic mean.
Mean is the only measure of central tendency where the sum of the deviations of each value from the mean is always zero.

How to find Mean of ungrouped data:

How to find Mean of grouped data:

How to find Mean in an array?

Given the n size array, find its mean.
Examples:

Input : {1, 3, 4, 2, 6, 5, 8, 7}
Output : Mean = 4.5
Explanation: Sum of the elements is 1 + 3 + 4 + 2 + 6 + 5 + 8 + 7 = 36, Mean = 36/8 = 4.5

Input : {4, 4, 4, 4, 4}
Output : Mean = 4

Approach:

Formula used:

Mean of an array = (sum of all elements) / (number of elements)

Follow the steps below for implementation:

Iterate over the array and keep adding elements to a variable sum
Divide the sum by the size of given array.

Below is the implementation of the above approach

C++

// CPP program to find mean
#include <bits/stdc++.h>
using namespace std;

// Function for calculating mean
double findMean(int a[], int n)
{
    int sum = 0;
    for (int i = 0; i < n; i++)
        sum += a[i];

    return (double)sum / (double)n;
}

// Driver program
int main()
{
    int a[] = { 1, 3, 4, 2, 7, 5, 8, 6 };
    int n = sizeof(a) / sizeof(a[0]);
    cout << "Mean = " << findMean(a, n) << endl;
    return 0;
}

Java

// Java program to find mean
import java.util.*;

class GFG {

    // Function for calculating mean
    public static double findMean(int a[], int n)
    {
        int sum = 0;
        for (int i = 0; i < n; i++)
            sum += a[i];

        return (double)sum / (double)n;
    }

    // Driver program
    public static void main(String args[])
    {
        int a[] = { 1, 3, 4, 2, 7, 5, 8, 6 };
        int n = a.length;
        System.out.println("Mean = " + findMean(a, n));
    }
}

Python

# Python3 program to find mean

# Function for calculating mean


def findMean(a, n):

    sum = 0
    for i in range(0, n):
        sum += a[i]

    return float(sum / n)


# Driver program
a = [1, 3, 4, 2, 7, 5, 8, 6]
n = len(a)
print("Mean =", findMean(a, n))

// C# program to find mean
using System;

class GFG {
    // Function for
    // calculating mean
    public static double findMean(int[] a, int n)
    {
        int sum = 0;
        for (int i = 0; i < n; i++)
            sum += a[i];

        return (double)sum / (double)n;
    }

    // Driver Code
    public static void Main()
    {
        int[] a = { 1, 3, 4, 2, 7, 5, 8, 6 };
        int n = a.Length;
        Console.Write("Mean = " + findMean(a, n) + "\n");
    }
}

JavaScript

// JavaScript program to find mean

// Function for calculating mean
function findMean(a, n)
{
    let sum = 0
    for (var i = 0; i < n; i++)
        sum += a[i]

    return (sum / n)
}

// Driver program
let a = [1, 3, 4, 2, 7, 5, 8, 6]
let n = a.length
console.log("Mean =", findMean(a, n))

// This code is contributed by phasing17

PHP

<?php 
// PHP program to find mean 

// Function for calculating mean
function findMean(&$a, $n)
{
    $sum = 0;
    for ($i = 0; $i < $n; $i++) 
        $sum += $a[$i];
    
    return (double)$sum / 
           (double)$n;
}

// Driver Code
$a = array(1, 3, 4, 2, 
           7, 5, 8, 6);
$n = sizeof($a);
echo "Mean = " . 
      findMean($a, $n)."\n"; 
?>