The margin requirement on the S\&P 500 futures contract is 16%, and the stock index is currently 1,600 . Each contract has a multiplier of $250. a. How much margin must be put up for each contract sold? Margin $ b. If the futures price falls by 2% to 1,568 , what will happen to the margin account of an investor who holds one contract? (Input the amount as a positive value.) Margin account by $ c-1. What will be the investor's percentage return based on the amount put up as margin? (Negative value should be indicated by a minus sign. Round your answer to 2 decimal places.) Percentage return % c-2. What would be the current cash balance in the margin account? Cash balance $