Lowest Resonant Frequency Issues

[Hypnos_16]

Homework Statement

A 138 cm length of string has a mass of 4.98 g. It is stretched with a tension of 6.35 N between fixed supports. What is the wave speed for this string?

What is the lowest resonant frequency of that wave?

(wavelength) = 138cm = 1.38m
M = 4.98g = 0.00498kg
Ft = 6.35N
v = 41.9m/s
(It's a two part question, i already know the speed is right, it's the second half I'm having trouble with)

Homework Equations

I've tried all the equations i can think of that have ƒ in them
(Wavelength) = (1 / ƒ) * ( √(T / µ))

V = (Wavelength) / T
ƒ = 1 / T

The Attempt at a Solution

(Wavelength) = (1 / ƒ) * (√ T / µ)
(Wavelength) = (1 / ƒ) * (v)
(Wavelength) = (1 / ƒ) * (41.9)
(1.38)(41.9) = (1 / ƒ)
(0.0329) = (1 / ƒ)
ƒ = 30.4Hz

that's always the answer i get no matter what i try, and it's always wrong.
What's going on?

 

[revnaknuma]

do you play a string instrument such as guitar or violin?

 

[Hypnos_16]

No, no i do not.