You need three more lines of code abline(h=0) xx <- seq(1.96, 4, length=25) polygon(x=c(xx[1],xx,xx[25]), y=c(0,dnorm(xx),0), col='red')
Please see the normal.and.t.dist function in the HH package for more detailed control of the graph. ## install.packages("HH") ## if you don't have it yet. library(HH) normal.and.t.dist(alpha.right=.025) [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.