title: Dividing summed field by another summed field in the same query
body: <p>How to divide a summed field by another summed field in the same query. </p>
  
  <p>Example: lets have the query "querySummary" which its field have been grouped already </p>
  
  <pre><code>  SID      SumOfCredits     SumOfMarks
    1            3                18
    2            2                20
    3            4                40
  Group By      Sum               Sum
  </code></pre>
  
  <p>I want to add another field named "FAvg" to the same query that builds up of dividing "SumOfMarks" by SumOfCredits, so the the result should be as following </p>
  
  <pre><code>SID      SumOfCredits     SumOfMarks      FAvg
  1            3                18           6
  2            2                20           10
  3            2                40           20
  </code></pre>
  
  <p>Any help please ? many Thanks  </p>