A baseball team plays in a stadium that holds \( 50000 \) spectators. With the ticket price at \( \$ 10 \) the average attendance has been \( 19000 \) . When the price dropped to \( \$ 7 , \) the average attendance rose to \( 25000 . \) Assume that attendance is linearly related to ticket price. 

What ticket price would maximize revenue?  $\(\square\)