Wavelength = (speed) / (frequency)
So you see, the wavelength is also going to depend on the wave's speed, which you didn't tell us.
-- If the wave is traveling in iron, its speed is about 5,120 m/s.
Wavelength in iron = (5,120 m/s / 250 Hz)
Wavelength in iron = 20.48 meters
-- If the wave is traveling in water, its speed is about 1,480 m/s .
Wavelength in water = (1,480 m/s / 250 Hz)
Wavelength in water = 5.92 meters
-- If the wave is traveling in air, its speed is about 340 m/s .
Wavelength in air = (340 m/s / 250 Hz)
Wavelength in air = 1.36 meters
