Field progress value

I’m a new user of phprad and I’ve only been using it for a short time, sorry for my Google English. I have a table with the quantities ordered and the quantities made, on the list page I would like to insert a progress where for the quantities made field where the MAX value is the value I take from the quantities ordered field. I can’t find any automatic mechanisms for my needs and I tried with MAX <?php echo intval($data['quantity_ordered']); ?> but it gives me an error.
Thank you