Hello, I have a question on part by of this homework. I have attached my proof for the problem and my answer. From another tutor I received a different answer than I calculated. Are these answers equivalent, mine less simplified? Or are there errors in my proof. Any clarification would be great.

Homework Problems 1. Consider the Simple Linear Regression (SLR) model yi = Bo + Bili + Ei, where the eis have zero mean, variance o and are uncorrelated. Sometimes it is convenient to write the SLR model in the following way: yi = Bo+ Bidi + Ei = Bo + Bili - Bia + Biate; = (Bo + BIT) +Bi (x; - x) + ; = a + Bi (xi - x) +; where we have defined o := Bo + Bit, with a = (Et_, x.). (a) What is the meaning of the parameter a? (b) Derive the least-squares estimators for o and B1. A. parameter a is the intercept term B. derive least squares estimators for a + Bi JRSS = 0 - 2 2 ( yi- Q - Bi(xi- x ) fox JRSS= 0 -2 2 (yi -Qx-Bi (xi-x)) .xi-x XP for a : Zyi = Ex + [Bi(xi-x ) no = Zui- ZBi (xi-x) a = zyl - ZBi( xi-x) = -zyi - Bin z(xi- x) n * =Tyn - Bn.Z(xi-x) o= Y- Bi (xi-x) For Bi: aE (x - * ) + Biz(xi-x)"= zyifxi-x) ( y - Birxi -*) z(xi-x )+ Biz(xi -x)2 = Zyifxi-x) my answer - Bilxi - x ) E ( xi - x ) + Biz ( xi - > ) 2 = zyilxi- x ) - uelxi-x ) Bi ( z( xi - x ) 2 - ( xi-x ) E ( xi - x ) = =yi(xi-x ) - q= (xi-x) BI = Zyi (Xi- x) - GE(xi-x) E ( xi - 8 ) 2 - ( xi- x ) ( z ( x - x ) For B , LS estimator , answer given by tutor was B, = = ( xi-x) ( yi- y ) 2(xi-x ) 2