posed to be numeric (validity)</li>
</ul>
<p>On the other hand, the following warnings are not really necessary:</p>
<ul>
<li>Noting that some of the levels of the <code>stateOfBirth</code> variable has less than five observations.</li>
<li>There is a warning about the variable <code>sex</code> only containing one level (“male”), but this is not a mistake in the data</li>
<li>In the <code>ethnicity</code> variable, the value <code>African American</code> has less than five observations. However, this is