sult, it’s important to use all constituent terms in the model even if they are thought <em>a priori</em> to have coefficients of zero. Now let’s see how we can use <code><a href="../reference/margins.html">margins()</a></code> to interpret a more complex three-way interaction:</p>
<div class="sourceCode"><pre class="sourceCode r"><code class="sourceCode r">x1 &lt;-<span class="st"> </span><span class="kw">lm</span>(mpg <span class="op">~</span><span class="st"> </span>drat <span class="op">*</span><spa