# Normal Distribution Probability Calculator

## Online Statistics Calculators - Solvers

### » Normal Distribution Probability Calculations

You can Use this calculator if you want to compute a probabilities associated with the normal distribution. You need to know the population mean μ
and the population standard deviation σ. You need to provide information about the event you want to compute the probability. The script will also provide a picture of the shaded area.

[insert_php]
$root_path = "/home/timeofwa/homeworkfactory.com"; require_once$root_path . "/wp-content/php_includes/FormFunctions.php";
$solver_name = "normalcalculation"; echo_form_start(); //Start form with its styling echo_anchor_results(); //The point where the browser will scroll for the results echo_begin_div_table(750); input_line('Population Mean ($$\mu$$)','mean',100,45); //Basic input line for text input_line('Population St. Dev. ($$\sigma$$)','sigma',101); //Basic input line for text echo_end_div_table(); probability_event_input(102); //Function to define a probabilistic event echo_hidden_input($solver_name); //Sometimes used for validation, it may disappear
echo_submit("Calculate",106); //Submit button
echo_form_end(); //Ends form
[/insert_php]

[insert_php]
if ($_SERVER['REQUEST_METHOD'] == 'POST' &&$_POST[$solver_name] ==$solver_name){
//*******************************
//We retrieve POST parameters
//*******************************
$mean =$_POST['mean'];
$sigma =$_POST['sigma'];
$tail =$_POST['tail'];

if($tail=='twotailed'){$lower = $_POST['LeftLimitTwoTailed'];$upper = $_POST['RightLimitTwoTailed']; } elseif($tail=='lefttailed'){
$lower = '';$upper = $_POST['RightLimit']; } else{$lower = $_POST['LeftLimit'];$upper = '';

}

//******************************************************
//CALL THE REQUIRED PHP LIBRARIES
//******************************************************
require_once $root_path . "/wp-content/MathLibraries/Solver_NormalProbabilityClass.php"; //**************************************** //RENDER THE SOLUTION AND ERRORS //**************************************** try{ //************************************************** //INSTANTIATE OBJECT, ECHO STEPS AND ERRORS //**************************************************$oSolver = new NormalProbabilityCalculator($mean,$sigma, $tail,$lower, $upper);$oSolver->EchoSteps();
$oSolver->EchoSpecificErrors(); } catch(Exception$e){
echo "Something went wrong: ", \$e->getMessage(), "\n";
}

}
[/insert_php]