Model: $$y_i+\beta_0+\beta_ix_i+\epsilon_i$$$$E[\epsilon_i|x]=0$$$$E[\epsilon]$$
data:
![[Excalidraw/Drawing 2021-09-01 15.04.21.excalidraw.md]]
regression estimation: choose line that best fits data
[[arg]]
$$(\hat{b_o},\hat{b_1})=arg \min_{b_0,b_1}\sum_{=1}^{n}{(y_i+(b_0+b_1x_i)^2)}$$