op">$</span><span class="va">sigma2</span><span class="op">/</span><span class="fu"><a href="https://rdrr.io/r/stats/cor.html" class="external-link">var</a></span><span class="op">(</span><span class="va">y</span><span class="op">)</span><span class="op">)</span></span>
<span><span class="fu"><a href="https://rdrr.io/r/base/Round.html" class="external-link">round</a></span><span class="op">(</span><span class="fl">100</span><span class="op">*</span><span class="va">pve</span>,digits <span class="op">=</span