Wave harmonics (calculate speed of wave)

[Pseudopro]

Homework Statement

A glass tube with one end open and the other closed is used in a resonance experiment to determine the speed of sound. A tuning fork of frequency 427 Hz is used and resonance is observed for air column lengths equal to 17.4 cm and 55.0 cm.
(a) What speed of sound does this experiment give?
(b) What is the end correction for this tube?

Homework Equations

wavelength = 4L/n where n = 1,3,5,...
v = f x wavelength

The Attempt at a Solution

I assumed fundamental and second harmonics.
v = 427 x 4 x 0.174
v = 427 x 4/3 x 0.55
Although the answers don't exactly match, they're pretty close. However, the book answer is 321m s^-1.

Could someone please help me arrive at the book answer or disprove it?

 

[Pseudopro]

It's alright - I've already worked it out.