an class="va">fev</span><span class="op">$</span><span class="va">fev</span>, strata <span class="op">=</span> <span class="va">fev</span><span class="op">$</span><span class="va">smoke</span>, above <span class="op">=</span> <span class="fl">2</span><span class="op">)</span></span></code></pre></div>
<pre><code><span><span class="co">##                      N     Msng  Mean      Std Dev    Min       25%     </span></span>
<span><span class="co">## fev$fev:  All          654     0   2.637     0.8671    0.79