8. substitutes, complements, or unrelated? you work for a marketing firm that has just landed a contract with run-of-the-mills to them promote three of their products: guppy gummies, flopsicles, and cannies. all of these products have been on the market for some time, but, to entice better sales, run-of-the-mills wants to try a new advertisement that will market two of the products that consumers will likely consume together. as a former economics student, you know that complements are typically consumed together while substitutes can take the place of other goods. run-of-the-mills provides your marketing firm with the following data: when the price of guppy gummies decreases by 5%, the quantity of flopsicles sold increases by 4% and the quantity of cannies sold decreases by 5%. your job is to use the cross-price elasticity between guppy gummies and the other goods to determine which goods your marketing firm should advertise together.