title: Why do the quartiles in summary differ to those calculated manually?
body: <p>Why do I get a different value when calculating the quartiles for my data set in R?</p>
  
  <p>These values are different </p>
  
  <pre><code>x &lt;- c(66,72,79,84,102,110,123,144,162,169,414)
  lowerQ &lt;- median(c(66,72,79,84,102)) ; lowerQ
  upperQ &lt;- median(c(123,144,162,169,414)) ; upperQ
  </code></pre>
  
  <p>to these values</p>
  
  <pre><code>quantile(x)
  summary(x)
  </code></pre>