"ch-centre-and-dispersion.html"><a href="ch-centre-and-dispersion.html"><i class="fa fa-check"></i><b>9</b> Centre and dispersion</a>
<ul>
<li class="chapter" data-level="9.1" data-path="ch-centre-and-dispersion.html"><a href="ch-centre-and-dispersion.html#introduction-4"><i class="fa fa-check"></i><b>9.1</b> Introduction</a></li>
<li class="chapter" data-level="9.2" data-path="ch-centre-and-dispersion.html"><a href="ch-centre-and-dispersion.html#symbols"><i class="fa fa-check"></i><b>9.2</b> Symbols</a></l