\begin{Schunk}
\begin{Sinput}
 dat <- dat[ dat$gradrate <= 100, ]
 datpublic  <- dat[dat$schtype %in% levels(dat$schtype)[1], ]
 datprivate <- dat[dat$schtype %in% levels(dat$schtype)[2], ]
 par(mfcol=c(1,2))
 hist(datpublic$gradrate, prob = TRUE, breaks = 50, main = "Public Graduation Rates")
 hist(datprivate$gradrate, prob = TRUE, breaks = 50, main = "Private Graduate Rates")
\end{Sinput}
\end{Schunk}
