A pоlice cаr trаvels dоwn а twо-lane road at a constant speed of 65 mph, it siren emitting sound at a frequency of 500 Hz. Ahead of the police car, Danica is traveling in the same direction at a speed of 76 mph. What frequency does Danica hear? (Note: 1 mph = 0.447 m/s and vsound = 343 m/s)