ToothGrowth <-
data.frame(len = c(4.2, 11.5, 7.3, 5.8, 6.4, 10, 11.2, 11.2, 5.2, 7,
16.5, 16.5, 15.2, 17.3, 22.5, 17.3, 13.6, 14.5, 18.8, 15.5, 23.6, 18.5,
33.9, 25.5, 26.4, 32.5, 26.7, 21.5, 23.3, 29.5, 15.2, 21.5, 17.6, 9.7,
14.5, 10, 8.2, 9.4, 16.5, 9.7, 19.7, 23.3, 23.6, 26.4, 20, 25.2, 25.8,
21.2, 14.5, 27.3, 25.5, 26.4, 22.4, 24.5, 24.8, 30.9, 26.4, 27.3, 29.4,
23), supp = factor(c(2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1),
levels=1:2, labels = c("OJ", "VC")), dose = c(0.5, 0.5, 0.5, 0.5, 0.5,
0.5, 0.5, 0.5, 0.5, 0.5, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2))