Hi I'm working on this OLS regression model problem I have started the question by calculating the b1 estimator but I have a different identity to the one used in the model answers, which I have also attached below. How do I derive what they have in the model question?
$\begingroup$ what have you tried? also consider adding the 'self-study' tag. $\endgroup$– utobiDec 23, 2022 at 17:14