title: MySQL Math - Is it possible to calculate a correlation in a query?
body: <p>In a MySQL (5.1) database table there is data that represents:</p>
  
  <ul>
  <li>how long a user takes to perform a task and </li>
  <li>how many items the user handled during the task.</li>
  </ul>
  
  <p>Would MySQL support correlating the data or do I need to use PHP/C# to calcuate?</p>
  
  <p>Where would I find a good formula to calculate correlation (it's been a long time since I last did this)?</p>