A manufacturer of tortilla chips is launching a blue chip made with blue corn.They reached an agreement with a local grocery chain to allow them to use different displays for the new chips in 4 of the chain's stores.The sales (bags) in the stores were tracked for 6 weeks, one store was closed for a week because of a fire caused by their red-hot salsa.We assume that all 4 stores serve similarly sized markets and their weekly sales of other products are similar. Are the displays equally effective or does one differ from the others?You do not have to identify which one.