# \[PHP\]Mean Average & Standard Deviation

**URL:** https://forum.kirupa.com/t/php-mean-average-standard-deviation/215800
**Category:** open source
**Created:** [February 10, 2007, 1:58pm UTC](https://forum.kirupa.com/t/php-mean-average-standard-deviation/215800 "2007-02-10T13:58:07Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![evildrummer](https://yyz1.discourse-cdn.com/flex011/user_avatar/forum.kirupa.com/evildrummer/32/2308_2.png) [@evildrummer](https://forum.kirupa.com/u/evildrummer)
#### Post date: [February 10, 2007, 1:58pm UTC](https://forum.kirupa.com/t/php-mean-average-standard-deviation/215800/1 "2007-02-10T13:58:07Z")

</div>

For some stats revision I made these, you may like them,

For more information + source code go to the relevant link:  
[http://blog.digitalcarnival.com/2007/02/10/php-mean-average/](http://blog.digitalcarnival.com/2007/02/10/php-mean-average/)  
[http://blog.digitalcarnival.com/2007/02/10/php-standard-deviation/](http://blog.digitalcarnival.com/2007/02/10/php-standard-deviation/)

and previews:  
[http://php.digitalcarnival.com/meancalc.html](http://php.digitalcarnival.com/meancalc.html)  
[http://php.digitalcarnival.com/sdcalc.html](http://php.digitalcarnival.com/sdcalc.html)

\*\*FUNCTIONS:  
\*\*

```php

function mean($x) {
$summation = 0;
$values = 0;
    foreach ($x as $value) {
        if (is_numeric($value)) {
            $total = $total + $value;
            $values++;
        }
    }
    $mean = $total/$values;
    return $mean;
}

function standard_deviation($x) {
$summation = 0;
$values = 0;
    foreach ($x as $value) {
        if (is_numeric($value)) {
            $summation = $summation + $value;
            $values++;
        }
    }
    $mean = $summation/$values;
    foreach ($x as $value) {
        if (is_numeric($value)) {
            $ex2 = $ex2 + ($value*$value);
        }
    }
    $rawsd = ($ex2/$values) - ($mean * $mean);
    $sd = sqrt($rawsd);
    return $sd;
}

```