title: Excel - Wrong result when finding simple quartile exercise
body: <p>I have the following values places in row 1 (cell <code>A1</code> to cell <code>L1</code>):</p>
  <p><code>1  1   2   3   4   5   6   7   7   7   8   10</code></p>
  <p>I can find the 1st, 2nd, 3rd and 4th quartiles using:</p>
  <pre><code>=QUARTILE(A1:L1,1)
  =QUARTILE(A1:L1,2)
  =QUARTILE(A1:L1,3)
  =QUARTILE(A1:L1,4)
  </code></pre>
  <p>Based on my calculation by hand and some online calculator, the values, respectively, should be <code>2.5</code>, <code>5.5</code>, <code>7</code> and <code>10</code>. However, Excel gives <code>2.75</code> for 1st quartile. I should mention that the Excel sheet used is the default sheet without changing the formatting of any cell. Why is that?</p>