# R-program for Supplementary Exercise 7.68 of IPS7e

lessons <- read.csv("c:/data.avc/teaching/vhm801/07P/ex07_058.csv")

binom.test( sum(lessons$change>0), sum(lessons$change!=0), 0.5, alternative="greater")
# alternatively, the longer and more intuitive form:
x <- sum(lessons$change>0)
n <- sum(lessons$change!=0)
binom.test(x, n, 0.5, alternative="greater")