title: Rails have to create a "fake" column in model
body: <p>In my tabel I have:</p>
  
  <pre><code>rating_score =&gt; The current score
  ratings =&gt; The number of ratings which led to the score
  </code></pre>
  
  <p>I want to create a "fake" column named rating which is (rating_score/ratings) in model. That I can use in my controller to order after and in my view.</p>
  
  <p>How should I create this in my model?</p>