\begin{Schunk}
\begin{Sinput}
 df <- cbind(top=c(summary(x1), mean=mean(x1),sd=sd(x1), sd.over.mean=sd(x1)/mean(x1)), bottom=c(summary(x2),mean(x2), sd(x2),sd(x2)/mean(x2)))
 #means <- round(mean(df),2)
 #sds <- round(sd(df),2)
 #sd.over.mean <- round(sds/means,2)
 #df2 <- rbind(as.data.frame(summary(df)),means, sds, sd.over.mean)
\end{Sinput}
\end{Schunk}
