uot; (stateOfBirth).
pd[pd$lastName == &quot;Trump&quot;, &quot;stateOfBirth&quot;] &lt;- &quot;New York&quot;

#We fix the following mistake:
#Truman&#39;s last name is prefixed with whitespace (lastName).
pd[pd$lastName == &quot; Truman&quot;, &quot;lastName&quot;] &lt;- &quot;Truman&quot;

#We fix the following mistake:
#ageAtInauguration is coded as a character variable.
pd$ageAtInauguration &lt;- as.numeric(pd$ageAtInauguration)

#We fix the following mistake:
#James  Garfield&#39;s state of birth (sta