don <- read.table("https://husson.github.io/livre_exo/chap8_ex3.csv", header = TRUE, sep=";",row.names=1, encoding = "latin1")

plot(y~x, data=don)
cor(don$y,don$x)
cor.test(don$y,don$x)

cor(don$y,don$x,method="spearman")
cor.test(don$y,don$x,method="spearman")