A craftsman is skilled in producing high-end wooden tables at a production cost of $50 per table. It's anticipated that if the tables are sold for p dollars each, customers will purchase = 120 tables per month. a. Express the craftsman's profit P as a function of q. b. What is the average rate of change in profit as the production level increases from q = 0 to q = 20 tables? c. Determine the rate of change in profit when q = 20 tables are produced. Is the profit increasing or decreasing at this production level?