Answer:
Wavelength,

Step-by-step explanation:
Given that,
Frequency of the sound wave, f = 17 Hz
It is heard 1000 km away in the ocean
The speed of sound is, v = 1531 m/s
Let
is the wavelength of sound in seawater. We know that the relation between frequency and wavelength is given by :




So, the wavelength of such a sound in seawater is 90.05 meters. Hence, this is the required solution.