Carl puts $ 10,000 into a bank account that pays an effective annual interest rate of 4% for ten years. If withdrawal is made during the first five and one half years, a penalty of 10 % of the withdrawal amount is made. Carl withdraws K at the end of each of years 4, 5, 6, and 7. The balance in the account at the end of year 10 is $ 10,000. Calculate K

Withdrawal amount K = $