">$</span><span class="va">ldl</span>, by <span class="op">=</span> <span class="va">mri</span><span class="op">$</span><span class="va">sex</span><span class="op">)</span></span></code></pre></div>
<pre><code><span><span class="co">## </span></span>
<span><span class="co">## Call:</span></span>
<span><span class="co">## ttest(var1 = mri$ldl, by = mri$sex)</span></span>
<span><span class="co">## </span></span>
<span><span class="co">## Two-sample t-test allowing for unequal variances :</span></span>
<span><