Starting six months after her grandson Robin's birth, Mrs. Devine made deposits of $210 into a trust fund every six months until Robin was eighteen years old. The trust fund provides for equal withdrawals at the end of each six months for three years, beginning six months after the last deposit. If interest is 5.91% compounded semi-annually, how much will Robin receive every six months? .... Robin will receive $ (Round the final answer to the nearest cent as needed. Round all intermediate values to six decimal places as needed.)