Box XXXXXXXXXXdescribes an experiment in which 30 rats were randomly assigned to three treatment groups. Group 1 was a control group, group 2had thyroxin added to their drinking water, and group 3 had...

Box (1950) describes an experiment in which 30 rats were randomly assigned to three treatment groups. Group 1 was a control group, group 2had thyroxin added to their drinking water, and group 3 had thiouraciladded to their drinking water. Whereas there were ten rats in each ofgroups 1 and 3, group 2 consisted of only seven rats (due to an unspecifiedaccident at the beginning of the experiment). The body weights of each ofthe 27 rats were recorded at the beginning of the experiment and at weeklyintervals for four weeks, as shown in Table 2.12. Test for differences amongthe three groups using an appropriate summary statistic.