\begin{Schunk}
\begin{Sinput}
 ### Theory says we should have 2.5% of the area to the left of: -1.96 * sigma.
 ### Find the X coordinate of that "critical value"
 criticalValue <- mu -1.96 * sigma
 criticalValue <- round(criticalValue, 2)
 ### Then grab all myx values that are "to the left" of that critical value.
 specialX <-  myx[myx <= criticalValue]
 ### mark the critical value in the graph
 text ( criticalValue, 0 ,
       label=criticalValue, pos=1)
\end{Sinput}
\end{Schunk}
