10. Alex purchases ten S&P 500 futures contracts. The S&P 500 futures price is 400 at the date of purchase. The margin requirement is 8%. The maintenance margin is 90%. The margin account earns 5.2% compounded continuously. The futures contracts are marked to market weekly. At the end of one week, the S&P 500 futures price is X and the amount in the margin account is exactly equal to the maintenance margin amount. Determine X. 11. Neil purchases ten S&P 500 Futures Contracts with a futures price of 1200. Neil's margin requirement is 12%. His maintenance margin is X%. The margin account earns 6% compounded continuously. The margin account is marked to market weekly. At the end of one week after the purchase, the S&P futures price has fallen to 1180. Neil's margin account is now 6,384.38 less than the maintenance margin. Determine X