Turn to the S&P 500 contract in Figure 22.1. Assume the closing price for this day. a. If the margin requirement is 18% of the futures price times the multiplier of $250, how much must you deposit with your broker to trade the June maturity contract? (Round your answer to 2 decimal places. Omit the "$" sign in your response.) b. If the June futures price were to increase to 1, 493.23, what percentage return would you earn on your net investment if you entered the long side of the contract at the price shown in the figure? (Do not round intermediate calculations. Round your answer to 2 decimal places. Omit the "%" sign in your response.) c. If the June futures price falls by 1%, what is your percentage return? (Negative amount should be indicated by a minus sign. Omit the "%" sign in your response.)