title: select random value based on probability chance
body: <p>How do I select a random row from the database based on the probability chance assigned to each row.<br>
  <em>Example:</em></p>
  
  <pre><code>Make        Chance  Value
  ALFA ROMEO  0.0024  20000
  AUDI        0.0338  35000
  BMW         0.0376  40000
  CHEVROLET   0.0087  15000
  CITROEN     0.016   15000
  ........
  </code></pre>
  
  <p>How do I select random make name and its value based on the probability it has to be chosen.</p>
  
  <p>Would a combination of <code>rand()</code> and <code>ORDER BY</code> work? If so what is the best way to do this?</p>