<div dir="ltr"><div class="gmail_default"><div class="gmail_default"><font face="verdana, sans-serif">From <a href="https://en.wikipedia.org/wiki/Median">wikipedia</a>.</font></div><div class="gmail_default"><span style="color:rgb(37,37,37);font-family:sans-serif;font-size:14px"> If there is an even number of observations, then there is no single middle value; the median is then usually defined to be the </span><a href="https://en.wikipedia.org/wiki/Arithmetic_mean" title="Arithmetic mean" style="text-decoration:none;color:rgb(11,0,128);background-image:none;font-family:sans-serif;font-size:14px">mean</a><span style="color:rgb(37,37,37);font-family:sans-serif;font-size:14px"> of the two middle values </span><sup id="cite_ref-StatisticalMedian_1-0" class="" style="line-height:1;font-size:11px;color:rgb(37,37,37);font-family:sans-serif"><a href="https://en.wikipedia.org/wiki/Median#cite_note-StatisticalMedian-1" style="text-decoration:none;color:rgb(11,0,128);background-image:none;white-space:nowrap">[1]</a></sup><span style="color:rgb(37,37,37);font-family:sans-serif;font-size:14px"> </span><sup id="cite_ref-2" class="" style="line-height:1;font-size:11px;color:rgb(37,37,37);font-family:sans-serif"><a href="https://en.wikipedia.org/wiki/Median#cite_note-2" style="text-decoration:none;color:rgb(11,0,128);background-image:none;white-space:nowrap">[2]</a></sup><span style="color:rgb(37,37,37);font-family:sans-serif;font-size:14px"> (the median of {3, 5, 7, 9} is (5 + 7) / 2 = 6), which corresponds to interpreting the median as the fully </span><a href="https://en.wikipedia.org/wiki/Trimmed_estimator" title="Trimmed estimator" style="text-decoration:none;color:rgb(11,0,128);background-image:none;font-family:sans-serif;font-size:14px">trimmed</a><span style="color:rgb(37,37,37);font-family:sans-serif;font-size:14px"> </span><a href="https://en.wikipedia.org/wiki/Mid-range" title="Mid-range" style="text-decoration:none;color:rgb(11,0,128);background-image:none;font-family:sans-serif;font-size:14px">mid-range</a><span style="color:rgb(37,37,37);font-family:sans-serif;font-size:14px">. </span><font face="verdana, sans-serif"><br></font></div><div class="gmail_default"><br></div><div class="gmail_default"><font color="#252525" face="sans-serif"><span style="font-size:14px"><br></span></font></div><div class="gmail_default"><span style="color:rgb(37,37,37);font-family:sans-serif;font-size:14px">Alan. </span></div></div></div>