<p>character variable with students' ratings of instructor (A-F)</p></dd>

<dt>gpa</dt>
<dd><p>students' grade point average</p></dd>


</dl></div>
    <div id="references">
    <h2>References</h2>
    <p>Kitchens, L. J. (2003) <em>Basic Statistics and Data Analysis</em>.
Pacific Grove, CA: Brooks/Cole, a division of Thomson Learning.</p>
    </div>

    <div id="ref-examples">
    <h2>Examples</h2>
    <div class="sourceCode"><pre class="sourceCode r"><code><span class="r-in"><span></span></span>
<span cla