The relationship between frequency, wavelength and speed of a wave is given by
[tex]v=\lambda f[/tex]
where
v is the wave speed
[tex]\lambda[/tex] is its wavelength
f is its frequency
for the wave in our problem, [tex]f=4.7 Hz[/tex] and [tex]\lambda=71.9 cm=0.719 m[/tex], so the speed of the wave is (using the previous equation)
[tex]v=\lambda f = (0.719 m)(4.7 Hz)=3.38 m/s[/tex]
