5) Consider the simple linear regression model N(0, o2) i = 1,...,n Let g be the...
2. Consider a simple linear regression model for a response variable Yi, a single predictor variable ri, i-1,... , n, and having Gaussian (i.e. normally distributed) errors Ý,-BzitEj, Ejį.i.d. N(0, σ2) This model is often called "regression through the origin" since E(Yi) 0 if xi 0 (a) Write down the likelihood function for the parameters β and σ2 (b) Find the MLEs for β and σ2, explicitly showing that they are unique maximizers of the likelihood function. (Hint: The function...
2. Consider a simple linear regression i ion model for a response variable Y, a single predictor variable ,i1.., n, and having Gaussian (i.e. normally distributed) errors: This model is often called "regression through the origin" since E(X) = 0 if xi = 0 (a) Write down the likelihood function for the parameters β and σ2 (b) Find the MLEs for β and σ2, explicitly showing that they are unique maximizers of the likelihood function Hint: The function g(x)log(x) +1-x...
linear regression model yi= a + bxi +ei calculate 95% confidence interval of b assuming ei ~N(0,o2)
Consider the least-squares residuals ei-yi-yi, 1, 2, . . . , linear regression model. Find the variance of the residuals Var(e). Is the vari- ance of the residuals a constant? Discuss. n,from the simple
1. Consider the simple linear regression model: Ү, — Во + B а; + Ei, where 1, . . , En are i.i.d. N(0,02), for i1,2,... ,n. Let b1 = s^y/8r and bo = Y - b1 t be the least squared estimators of B1 and Bo, respectively. We showed in class, that N(B; 02/) Y~N(BoB1 T;o2/n) and bi ~ are uncorrelated, i.e. o{Y;b} We also showed in class that bi and Y 0. = (a) Show that bo is...
Which of the following is NOT an assumption of the multiple regression model? Select one: a. E(ei)=0 E ( e i ) = 0 b. The values of each xik are not random and are not exact linear functions of the other explanatory variables. c. cov(yi,yj)=cov(ei,ej)=0;(i≠j) c o v ( y i , y j ) = c o v ( e i , e j ) = 0 ; ( i ≠ j ) d. var(yi)=var(ei)=σ2i
6. This problem considers the simple linear regression model, that is, a model with a single covariate r that has a linear relationship with a response y. This simple linear regression model is y = Bo + Bix +, where Bo and Bi are unknown constants, and a random error has normal distribution with mean 0 and unknown variance o' The covariate a is often controlled by data analyst and measured with negligible error, while y is a random variable....
2.25 Consider the simple linear regression model y = Bo + B x + E, with E(E) = 0, Var(e) = , and e uncorrelated. a. Show that Cov(Bo, B.) =-TOP/Sr. b. Show that Cov(5, B2)=0. in very short simple way
Regression analysis 1.3. Use the statistical model Yi Bo1Xi+ € to show that ei ~NID(0, o2) implies each of the following: (a) E(Y)Bo B1X, (b) 2(Y2, and (c) Cov(Y,Y)= 0, i i' For Parts (b) and (c), use the following definitions of variance and covariance o2(Y Y E(Y)]} Cov(Yi, Y) E{[Y-E(Y)Y- E(Y)] 1.3. Use the statistical model Yi Bo1Xi+ € to show that ei ~NID(0, o2) implies each of the following: (a) E(Y)Bo B1X, (b) 2(Y2, and (c) Cov(Y,Y)= 0,...
Simple linear regression model Assumptions: AI E[u] 0 for all i, i1, .., n On average, random component is zero Model runs through expected values of Yand Y A2 E[uaij]-0 for all i and j where i /j COV(IIİlh)- Unobserved component not related across observations E[14"]= for all i All observations have random component dravn from a distribution with the same variance σ2 , f(0,02) A3 var(11i)-σ (Homoskedasticitv) A4 E[Alli] = 0 for all i Random component and covariate not...