Apoultry specialist is conducting an experiment to determine whether the mean cholesterol content of egg yolks is affected by adding certain chemicals to the feed given to the hens laying those eggs. the 120 laying hens available for the study will be randomly allocated to three groups. each group of hens will be fed a ration with a different chemical additive and the cholesterol content of their eggs will be measured. what procedure should be used to compare the mean cholesterol content of the eggs for the three treatment groups of chemical additives?