When the first automobiles were built in 1901, they were manufactured by skilled workers using hand tools. Later, in 1913, Henry Ford introduced the moving assembly line, which lowered costs and speeded production. Over the years, the production line has become ever more mechanized, and today robots have replaced people in many operations.

a) Sketch the average total cost and the demand curve for automobiles in 1901.

b) Sketch the average total cost curve and the demand curve for automobiles in 1913.

c) Sketch the average total cost curve and the demand curve for automobiles in 2006.