You open a brokerage account on January 1 and sell short 500 shares of Apple Computer at $163.39 per share. The initial margin requirement is 50%. Assume that Apple pays an annual dividend on December 31 of $5.50 per share, the price of the stock is now $140 per share, assume you cover your short position on December 31. What is your rate of return? There is no interest paid in this margin account