6.4 Reiczigel (1999) analyzed an experiment that studies the effect of cholagogues on changes in gallbladder volume (GBV) of dogs. The experiment used two different cholagogues (A and B) and tap water (W) as a control. Six healthy dogs were assigned to each treatment. The GBVs were measured by ultrasound every ten minutes for two hours. The data follow.

(a) It is probably reasonable to assume an AR(1); therefore perform a thorough analysis of these data using this assumption.

(b) Repeat part

(a) using the robust approach.

(c) Discuss any differences, if any, in these two analyses.