\begin{Schunk}
\begin{Sinput}
 y1p.range <- range(y1p)
 par(mfcol = c(2,2))
 hist(y1p, prob = TRUE, xlim = y1p.range, breaks=50, main = paste("Size =", size1))
 hist(y2p, prob = TRUE, xlim = y1p.range, breaks=50, main = paste("Size =", size2))
 hist(y3p, prob = TRUE, xlim = y1p.range, breaks=50, main = paste("Size =", size3))
 hist(y4p, prob = TRUE, xlim = y1p.range, breaks=50, main = paste("Size =", size4))
\end{Sinput}
\end{Schunk}
