richshaw · April 5, 2016 19:00
diff --git a/index.php b/index.php
 <?php
 /**
 * Function to get confidence interval of proportions in PHP 
 * Based on https://onlinecourses.science.psu.edu/stat200/node/48
 */
 
 /**
  * Calculates CI, defaults to 95% z of 1.96
  * for 99% use z of 2.58
  */
  
 function ci($prop, $n, $z = 1.96) {
   //Std Error
   $se = sqrt($prop * (1 - $prop) / $n);
   return [$prop + $z  * $se,
           $prop - $z  * $se];
 }
 
 //Test
 $ci = ci(0.640,1168);
 //Returns [0.676,0.604]
	<?php
	/**
	* Function to get confidence interval of proportions in PHP
	* Based on https://onlinecourses.science.psu.edu/stat200/node/48
	*/

	/**
	* Calculates CI, defaults to 95% z of 1.96
	* for 99% use z of 2.58
	*/

	function ci($prop, $n, $z = 1.96) {
	//Std Error
	$se = sqrt($prop * (1 - $prop) / $n);
	return [$prop + $z * $se,
	$prop - $z * $se];
	}

	//Test
	$ci = ci(0.640,1168);
	//Returns [0.676,0.604]