\begin{Schunk}
\begin{Sinput}
 mean(dat$age, na.rm = TRUE)
\end{Sinput}
\begin{Soutput}
[1] 47.14159
\end{Soutput}
\begin{Sinput}
 range(dat$age, na.rm = TRUE)
\end{Sinput}
\begin{Soutput}
[1] 18 89
\end{Soutput}
\begin{Sinput}
 quantile(dat$age, na.rm = TRUE)
\end{Sinput}
\begin{Soutput}
  0%  25%  50%  75% 100% 
  18   34   46   59   89 
\end{Soutput}
\end{Schunk}
