Subject: Young's Modulus of a typical classroom wooden metre rule?

Hello, I'm doing an investigation trying to determine the young's modulus of a
classroom ruler. I was told (by a not so reliable source) that the value should
be 4.5 GPa. I thought this seemed a little low.
My experiments indicate a Young's modulus of 16 GPa.

So after that breif, here are my questions:
-Which value seems more correct, and what would your estimate be?
-For a classroom experiement measuring young's modulus with a loaded cantilever,
 what sort of level of accuracy should I be aiming for? (+/-  a few 100000
pascals, or even +/- a few giga pascals??)

Many Thanks for any advice, Im really stuck here.

Re: Young's Modulus of a typical classroom wooden metre rule?