# R-program for Supplementary Exercise 9.50 of IPS7e

empl <- read.csv("h:/vhm/vhm801/Datasets/csv/Chapter 9/ex09_050.csv")
empl.xtab <- xtabs(count ~ perf + over40, data=empl); empl.xtab
empl.chi2 <- chisq.test(empl.xtab); empl.chi2

# additional commands to retrieve the expected values and chi-square contributions
empl.chi2$expected
(empl.chi2$residuals)^2

# conditional distributions within columns
prop.table(empl.xtab, 2)