1 point Choose one that is not correct about the sample regression function (SRF). Since you don't know the population regression function in general, you can only estimate it from the SRF. At each Xi, the SRF may underestimate or overestimate the true population regression function. For each sample, you would get a different SRF. Moreover, these SRFs are likely to be different. SRFs are always linear in Xi's. Once you get an SRF from the data, you can calculate the residual 13?- from them: T172- 2 Y; 7 Y1