How to find the wavelength of a sound wave?

[strayaway]

Homework Statement

What is the wavelength of a 25 Hz sound wave? What is the wavelength of a 4.5 kHz sound wave?

Homework Equations

wavelength = velocity / frequency or λ = v/f

The Attempt at a Solution

I know that I'm supposed to plug the 25 into the equation, but he didn't give us a velocity, so now I'm stuck. That's what I need help with. :/
The speed of sound is 340 m/s
is that what I'm supposed to use for velocity?

 

[QuarkCharmer]

The speed of sound ?