smgrader-quiz-scoring

// http://www.gravityhelp.com/forums/topic/mathematics-to-gravity-forms
add_action('gform_pre_submission', 'ch_total_quiz_values');
function ch_total_quiz_values ($form) {
	// change the number 20 here to your form ID
	// if this is not form 20, don't do any processing
	if($form['id'] != 20)
		return $form;

	// otherwise ...
	$score = 0;
	// my radio button inputs are numbered 1 to 20.  Change the beginning
	// and ending number in this loop to match your actual input numbers
	for($i=1; $i<=20; $i++) {
		// add the value of the $_POST value for input 1 to input 20
		$input  = 'input_' . $i;
		$score += rgpost($input);
	}
	// update the hidden 'Score' field with our calculated score
	$_POST['input_25'] = $score;
	switch($score) {
		// my "admin only" Rating field to hold the display message based on the score is input_24
		case 0:
		case 1:
		case 2:
		case 3:
		case 4:
		case 5:
			$_POST['input_24'] = '5 or fewer correct answers: You\'re a Social Media beginner.';
			break;
		case 6:
		case 7:
		case 8:
		case 9:
		case 10:
			$_POST['input_24'] = '6 to 10 correct answers: You\'re a Social Media intermediate.';
			break;
		case 11:
		case 12:
		case 13:
		case 14:
		case 15:
			$_POST['input_24'] = '11 to 15 correct answers: You\'re a Social Media pro.';
			break;
		default:
			$_POST['input_24'] = 'More than 15 correct answers: You\'re a Social Media Expert';
	}
	return $form;
}