Question 1 a) Consider the following linear regression model estimated using Ordinary Least Squares: , = Bo + B,X, + B,X2 Derive a test of the overall statistical significance of this model. [25 marks] b) Consider the following regression model: Yi = Be + B1X1 + Ui Assume that the error term, u;, is characterised by E(ui|X;) # 0 and V(u{]X;) = 02. What are the consequences for Ordinary Least Squares estimation of this model? Explain your