It's hard to find contemporaneous evidence, because it was apparently revealed by an internal company focus group, but here's [0] the page from the company them

It's hard to find contemporaneous evidence, because it was apparently revealed by an internal company focus group, but here's [0] the page from the company themselves with the claim. It wasn't revealed at all until the founder's memoirs in 2007, and it wasn't reported widely until this [1] 2014 article. 0: https://awrestaurants.com/blog/aw-third-pound-burger-fractions https://awrestaurants.com/blog/aw-third-pound-burger-fractio... 1: https://www.nytimes.com/2014/07/27/magazine/why-do-americans-stink-at-math.html https://www.nytimes.com/2014/07/27/magazine/why-do-americans...