Typo on slide 59: should be transposed X? CONFIRMED

Below the conversation between myself and Abad on what I thought was a typo:


Dear professor,

Could it be that there is a typo in slide no. 59 of the first lecture (linear regression)?
In the line in the screenshot below, I think it should say: HY = X(X'X)^-1X'Y with H= X(X'X)^-1X' (so twice the transposed X at the end instead of the normal X).


And the answer:


Dear Karel:

Thanks a lot for noticing this typo, it should be the transpose at the end indeed.

Regards,

Ariel Alonso Abad