a. Is sally using a marginal approach to her hiring of inputs?
b. Does the approach adopted by sally also imply that she is following a MR = MC rule for finding a profits-maximizing output?
c. Sally’s distinguished professor of marking examines her procedures and suggests she is mistaken in her approach. He insists that she should instead measure the profit on each new worker/machine combination employed and stop adding new output as soon as the last one added earns a lower profit than the previous one. How would you evaluate his distinguished?