Calculating Percentages Error - php

Question

I am trying to fix this percent calculation, however it is just stumping me today.
Here is the code:
$entries = GFAPI::get_entries($form['id'], $search_criteria);
$score = 0;
$max = 0;
$percentage = array();
if(!empty($entries)) {
foreach ($entries as $entry) {
$score = GFSurvey::get_field_score($form_fields, $entry);
$max = end($form_fields['choices']);
if(empty($max['score'])) {
unset($form_fields['choices'][key($form_fields['choices'])]);
$max = end($form_fields['choices']);
}
$max = $max['score'];
$percentage[] = ($score / $max ) * 100;
}
}
$average = round(array_sum($percentage) / count($percentage), 2);
I have the form and i have Not Applicable radio buttons on the form. When a client fills out the form, sometimes on certain questions they need to be N/A because they do not apply and that does not need to counted in the overall total score.
So that is the report generated which the % is incorrect. That percent should read: 94%. In this picture you will see if you click on the graph you can see this:
Graph Once Clicked
It is showing the people who answered this question, and there are 20. There are a total of 5 max points for each person, or in this case I have the N/A box set for blank, which returns 0. What it is doing is totaling all the possible points which are 100. (20 people and 5 max points)
What I need it to do is NOT count the blank fields and in return give me for example in the image Graph Once Clicked there are only 5 people that answered so max points are 25. the total points is 23.5 so 23.5 / 25.

Answer 1

How about this code ? The total percentage of answered questions is in variable $total_percentage.
$entries = GFAPI::get_entries($form['id'], $search_criteria);
$score = 0;
$max = 0;
$total_max = $total_score = 0;
$percentage = array();
if(!empty($entries)) {
foreach ($entries as $entry) {
$score = GFSurvey::get_field_score($form_fields, $entry);
$max = end($form_fields['choices']);
if(empty($max['score'])) {
unset($form_fields['choices'][key($form_fields['choices'])]);
$max = end($form_fields['choices']);
}
$max = $max['score'];
if ($max) {
$total_score += $score;
$total_max += $max;
}
$percentage[] = ($score / $max ) * 100;
}
}
$average = round(array_sum($percentage) / count($percentage), 2);
$total_percentage = ($total_max > 0) ? round($total_score/$total_max/100, 2) : 0;