Underground Sandwiches, a sandwich shop, has the following marginal product curve (labelled MP) for its hourly production. 20 MARGINAL PRODUCT (Sandwiches per worker) 18 18 14 12 10 MP N 2 LABOUR (Workers) When labour increases from four to five workers, total product changes by 3 sandwiches _ per hour. Use the orange points (square symbol) to plot the production function on the following graph. Assume that if there are no workers, Underground Sandwiches does not have any output