3) How did online banking technology change the cost structure of banks in terms of variable and fixed costs? How did this affect the structure of the banking industry? 4) Suppose that a market is highly concentrated due to increasing returns to scale. How can high market concentration affect the way firms behave? Explain by giving an example. 5) Assume that a firm has a cost function given by C(q)=20+4q. a. What are firm's average costs? What are firm's marginal costs? b. At what level of output are average costs are minimized? c. What is the range of outputs that the firm experiences economies of scale?