Assume the reserve requirement is 10% and the mpc = 0.6 for the economy when a stock market downturn reduces aggregate demand by $100 billion. instructions: enter your answers as a whole number. a. suppose the federal reserve wants to increase investment demand to offset the reduction in aggregate demand. to accomplish this goal, how much does investment demand need to increase? $ billion b. to increase investment demand by the desired amount, the fed estimates that interest rates will need to by 4% and the money supply will need to by $200 billion. c. in order to achieve the $200 billion change in the money supply, the fed will make an of $ billion.