Using his margin account, which has interest compounding monthly,and borrowing the maximum 50% allowed, Warren sells short $3,000 of a common stock that pays dividends of $20 at 6 months and $15 at 18 months.The dividends are paid out of Warrens margin account.The initial margin requirement is 50% and the annual effective interest rate on deposits into the margin account is i=4%. At T=20 months, Warren closes his short position by repurchasing the stock for $2,650. Find Warrens annual yield for the 20-month investment.