Supermarkets would change the location of products like milk or bread to figure out where they maximize overall sales. Many people go to the store to buy milk and bread, those being everyday staples. It turns out that data shows if you place those products at the end of the supermarket, then overall sales increase as people navigate through many other products to get to the milk and bread. The experiment would have consisted in placing the milk and bread towards the entrance of the supermarket (one sample), towards the middle (second sample) and towards the end (the third sample). Comparing average total sales for those locations --with ANOVA-- would have told us whether there is a difference in revenues depending on product location. There is!!! After we know there is an impact in revenues, we proceed to figure out which location is most profitable overall: the end of the supermarket. Class, according to the textbook, what are necessary data conditions to apply ANOVA?