* commands for Problem 13.2 of VER

insheet using "H:\VHM\VHM811\henriks\ex13_02.csv"

* demonstration of confounding by breed
cs lame lowangle [fw=n] if breed=="tb"
cs lame lowangle [fw=n] if breed=="stb"
cs lame lowangle [fw=n], by(breed)

* association breed vs lowangle
tabulate breed lowangle [fw=n]

* association breed vs lame, overall and stratified by lowangle
tabulate breed lame [fw=n]
tabulate breed lame [fw=n] if lowangle==0
tabulate breed lame [fw=n] if lowangle==1