3. Machine Learning- please help

a. Discuss the implications that uncertainty in X would have on parameter estimates based on linear regression models. Should we care about error in X when fitting OLS regressions?

b) Provide a brief discussion on the concept of regression dilution.

c) Are there any linear regression models that account for uncertainty in $X$ and $Y$? Please do some independent research and cite your sources.

d) Distinguish between least squares and maximum likelihood in the context of linear regression models.