27. A big increase in government spending is an example of a a) positive demand shock b) positive supply shock c) negative demand shock d) negative supply shock 28. A firm has a tax burden of 0.8, a leverage ratio of 1.4, an interest burden of 0.6, and a return- on-sales ratio of 8%. The firm generates $2.52 in sales per dollar of assets. What is the firm's ROE? a) 9.7% b) 4.0% c) 13.5% d) 12.1% 29. Which of the following is not an example of fiscal policy? a) Social Security spending b) Medicare spending c) Fed purchases of Treasury securities d) Changes in the tax rate