Indicate how each of the following would shift the (1) marginal-cost curve, (2) average-variable-cost curve, (3) average-fixed-cost curve, and (4) average-total-cost curve of a manufacturing firm. in each case specify the direction of the shift. a. a reduction in business property taxes. b. an increase in the nominal of production workers. c. a decrease in the price of electricity. d. an increase in insurance rates on plant and equipmente. an increase in transportation costs.