ults table, it is actually quite difficult to understand the effect of <code>wt</code> on fuel economy because it requires performing mental multiplication and addition on all possible values of <code>wt</code>. Using the <code>at</code> option to margins, you could quickly obtain a sense of the average marginal effect of <code>wt</code> at a range of plausible values:</p>
<div class="sourceCode"><pre class="sourceCode r"><code class="sourceCode r"><span class="kw"><a href="../reference/margins.html">margin