title: Finding standard deviation using only mean, min, max?
body: <p>I want to find the standard deviation:</p>
  
  <pre><code>Minimum = 5
  Mean = 24
  Maximum = 84
  
  Overall score = 90
  </code></pre>
  
  <p>I just want to find out my grade by using the standard deviation</p>
  
  <p>Thanks,</p>