The following diagram shows three possible SRATC curves and an LRAC curve for a single firm producing light bulbs, where each SRATC curve is associated with a different-sized plant.

a. If the firm is producing Q1 light bulbs with Plant #1, what are the firm's average costs?
b. At Q1, does the firm display decreasing, constant, or increasing costs?
c. How does your answer in part (b) relate to the concept of economies of scale?
d. Repeat parts (a), (b), and (c) for output level Q2 with Plant #2 and output level Q3 with Plant #3.