Two geometric sequences a_{1}, a_{2}, a_{3}, \ldots and b_{1}, b_{2}, b_{3}, \ldots have the same common ratio, with a_{1}=27, b_{1}=99, and a_{15}=b_{11}. Find a_{9}.
Two geometric sequences a_{1}, a_{2}, a_{3}, \ldots and b_{1}, b_{2}, b_{3}, \ldots have the same common ratio, with a_{1}=27, b_{1}=99, and a_{15}=b_{11}. Find a_{9}.