##### R-code for making Figure 3.4

xbar = c(-2.3,-1.6,-0.2,0.34,1.67,2.12,1.54,0.57,-0.23,-1.64,-2.15,
         -1.46,-0.18,0.76,1.29,1.99,1.46,0.34,-0.45,-1.76)
i <- seq(1,20)
U=3
C=0
L=-3

postscript("fig34.ps",width=4.5,height=4,horizontal=F)

plot(i,xbar,type="o",lty=1,pch=16,xlab="i",ylab=expression(bar(X)[i]),
     mgp=c(2,1,0),xlim=c(0,20), ylim=c(-3.2,3.2), yaxt="n",cex=0.8)
lines(i[21:24],xbar[21:24],type="o",lty=3,pch=1,cex=0.8)
lines(i,rep(U,length(i)),lty=2,cex=0.8)
lines(i,rep(C,length(i)),lty=2,cex=0.8)
lines(i,rep(L,length(i)),lty=2,cex=0.8)
axis(4,at=c(-3,0,3),labels=c("L","C","U"),cex=0.8,las=1)

graphics.off()