Can anyone help with an Econometrics Question?

[EconometricsQuestion]

For part c, given that we've only established E(ui) =0 and not E(ui|x) =0 in part B how can we know that the transformed model satisfies mlr. 1-ml4 and thus easily say the new estimator is unbiased without further technical proofs for part c.

Hopeful bump!

Can't help, but you would probably have more luck on Reddit. I know there is a maths sub, maybe an eco one too!

@Bearbookagainandagain
Thank you so much. Great ideas.