\begin{Schunk}
\begin{Sinput}
 x <- 68:87
 y <- dnorm(x, m = 78, sd = 2)
 plot(x, y, type = "l", xlim = c(60, 95), lty = 4, xlab = "Mean Test Scores", 
      ylab = "Chance of Observing Means")
\end{Sinput}
\end{Schunk}
