In the following cases, explain what happens to demand or quantity demanded and how the change would be shown on a graph of the demand schedule.
I. Assuming that tickets to an NFL game are normal goods, what is the effect of an increase in the incomes of NFL fans?
II. Assuming that Direct TV and Dish satellite are substitutes, what happens if the price of a Direct TV subscription increases?
III. Assuming that data plans and cell phones are complements, what happens if the price of data plans decreases?