# Paired data example, textbook prices at UCLA vs Amazon
texts=read.table("textbooks.txt",header=TRUE)
attach(texts)
diff=uclaNew-amazNew
diff
mu0=0
alpha=.05
t.test(diff,mu=mu0,conf.level=(1-alpha))

boxplot(diff)
abline(h=mu0,lty=2)

detach(texts)