BC;">11</span> hp           8 range_1 150  </span>
<span class="r-out co"><span class="r-pr">#&gt;</span> <span style="color: #BCBCBC;">12</span> hp           8 range_2 335  </span>
<span class="r-in"><span><span class="co"># More than one grouping variable -- 4 ways.</span></span></span>
<span class="r-in"><span><span class="fu">df_stats</span><span class="op">(</span> <span class="va">hp</span> <span class="op">~</span> <span class="va">cyl</span> <span class="op">+</span> <span class="va">gear</span>, da