average of multiple fivestar votings

Hey there,
I'm new to Drupal and to the Fivestar module. I already did some cool things with it, but now I've got a problem I can't solve. I already searched through umpteen issues on drupal.org, but I couldn't find the answer so far.

I attached a screenshot which should show what I want to reach on my Drupal site: a user creates a product review and rates several things like "price" or "quality". I realized this with fields in my content type. Those 4 ratings I could show in my node.tpl.php with this code: print $node->field_mycckfield[0]['view'] No problems so far. But now I want to show the average (on the screenshot "gesamt" [german]) of the 4 ratings. And that's my problem. I tried several codes from drupal.org and how you can see on the screenshot none of them really worked.

So please tell me, if it is possible to realize this with an easy piece of code or do I need further knowledge in javascript?

Greets,

Nico

Excuse me if there already are issues with the same topic...