Suppose that a risk-free investment will make three future payments of $250 in 1 year, $250 in 2 years, and $250 in 3 years. Instructions: Round your answers to 2 decimal places. a. If the Federal Reserve has set the risk-free interest rate at 4 percent, what is the proper current price of this investment? $ b. What is the price of this investment if the Federal Reserve raises the risk-free interest rate to 6 percent? $