">;</span></pre></div>
<div class="refsect1">
<a name="id-1.3.2.6.3.57.37.4"></a><h2>Description</h2>
<p>The kurtosis of a sample distribution is defined as the ratio of the 4th central moment and the square of the 2nd central moment (the variance) of the samples, minus 3. The term <span class="inlinemediaobject"><img src="../../../images/accumulators//form_41.png"></span> is added in order to ensure that the normal distribution has zero kurtosis. The kurtosis can also be expressed by the simple moments:</p