Make Q-Q plots for other pairs of treatment groups from Bjerkdahl’s data (see Example A...

Make Q-Q plots for other pairs of treatment groups from Bjerkdahl’s data (see Example A in Section 10.2.2). Does the model of a multiplicative effect appear reasonable?

Reference

As an example, let us consider the use of the survival function with a study of the lifetimes of guinea pigs infected with varying doses of tubercle bacilli (Bjerkdal 1960). In one study, five groups of 72 animals each were inoculated with the bacilli at increasing dosages, and a control group of 107 animals was used. We denote the inoculated groups by I, II, III, IV, and V, in order of increasing dose. The animals were observed over a 2-year period, and their times of death (in days) were recorded. The data are given here. Note that not all the animals in the lower-dosage regimens died.