4. (22 points) Assume that the long-run aggregate supply curve is vertical at Y: 3,000 while the short-run aggregate supply curve is horizontal at P = 1.0. The aggregate demand curve is Y = 2(M/P) and M = 1,500. Assume the economy is initially in long- run equilibrium, i.e. Y=3000 and P=l .0. a. If M increases to 2,000, what are the short-run values of P and l"? (6 points) b. Once the economy adjusts to long-run equilibrium at M = 2,000, what are P and I"? (6 points) c. Use a chart with curves of aggregate demand and aggregate supply (both short run and long-run aggregate supplyr curves} to show the impact of the increase of M on P and Y. (10 points)