\begin{Schunk}
\begin{Sinput}
 ss <- 0.1 * max(myDensity)
 ### Mark interval from mu to mu-1.96*sigma
 arrows( x0 = mu, y0 = ss, x1 = mu-1.96*sigma, y1 = ss, code = 3, angle = 90, length = 0.1)
 ### Put text above interval
 text( mu - 2.0*sigma,1.15*ss, bquote(paste(.(criticalValue), phantom(1)==mu-1.96 * sigma,sep="")), pos=4)
\end{Sinput}
\end{Schunk}
