\begin{Schunk}
\begin{Sinput}
 STDE = 400; b0 = 3; b1 = .2; b2 = -0.075
 x <- runif(400, 0, 100)
 x <- x[order(x)]
 dat <- data.frame(x)
 dat$xsq <- x*x
 dat$y <- b0 + b1 * dat$x + b2 * dat$xsq + rnorm(400, m=0, s = STDE)
 rm(x)
 xcorr <- cor(dat$x, dat$xsq)
\end{Sinput}
\end{Schunk}
