Two out-of-tune flutes play the same note. One produces a tone that has a frequency of 246 Hz, while the other produces 289 Hz. When a tuning fork is sounded together with the 246-Hz tone, a beat frequency of 18.0 Hz is produced. When the same tuning fork is sounded together with the 289-Hz tone, a beat frequency of 25.0 Hz is produced. What is the frequency of the tuning fork