
<dl><dt><span class="strong">Returns:</span></dt><dd>sum of squared deviations of y values</dd></dl>
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<h4>getXSumSquares</h4>
<pre>public&nbsp;double&nbsp;getXSumSquares()</pre>
<div class="block">Returns the sum of squared deviations of the x values about their mean.

 If <code>n < 2</code>, this returns <code>Double.NaN</code>.</p></div>
<dl><dt><span class="strong">Returns:</span></dt><dd>sum of squared 