Answer: -12%
Step-by-step explanation:
The cross-price elasticity between penguin patties and flopsicles is -12%, indicating that they are substitutes. The cross-price elasticity between penguin patties and kipples is 12%, indicating that they are complements. Therefore, the marketing firm should recommend marketing kipples with penguin patties, as they are complements and will see an increase in demand when one is purchased.