A long futures contract for 100 ounces in gold is opened at the end of trading on December 5, 2006. The contract is for June 2007 delivery. The following table gives the futures price and the gold spot price on successive days. The margin required is $3375 and the maintenance margin is $2500. If the margin balance drops below the maintenance margin, a margin call is made requiring the investor deposit enough to bring the margin account balance to the initial margin. Assuming there is no interest on the margin account, what is the profit if the investor closes out the position on: a) December 6 b) December 7