1. (Maple worksheet)

2. 1. Seats are priced so as to equate marginal revenue with marginal cost, provided there are enough seats to reach this point. So there are two possibilities:
      1. Marginal revenue equals marginal cost, and some seats are left empty.
      2. Marginal revenue exceeds marginal cost, and the ballpark is full.
      The relevant marginal cost is the cost of putting a body in a seat. This is probably negative, because although the cost of cleaning and maintenance increases with the number of tickets sold, this is probably outweighed by the increased concession revenue.
   2. Player salaries were not mentioned in part a, so an increase in player salaries has no effect on ticket pricing. The team makes less profit, but an increase in ticket prices would reduce profit even more, since tickets were already priced so as to maximize net revenue from ticket sales and concessions, and there has been no change in the determinants of ticket revenue and concession revenue.

3. (Maple worksheet)