2. Consider a simple linear regression model for a response variable Yi, a single predictor variable...
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...
Hi all, I need help with these questions. Here is my work so far and in b am having trouble showing it is a "unique" maximizer for variance. I would also appreciate it if someone with a good heard can also do the rest of the problems. Thank you in advance. 2. Consider a simple linear regression model for a response variable Y, a single predictor variable xi, i-1,..., n, and having Gaussian (i.e. normally distributed) errors: -Bai +Ej, Eii.i.d....
5) Consider the simple linear regression model N(0, o2) i = 1,...,n Let g be the mean of the yi, and let â and ß be the MLES of a and B, respectively. Let yi = â-+ Bxi be the fitted values, and let e; = yi -yi be the residuals a) What is Cov(j, B) b) What is Cov(â, ß) c) Show that 1 ei = 0 d) Show that _1 x;e; = 0 e) Show that 1iei =...
Please help with question 4 Consider the simple linear regression model: with σ2 is known. Assume x's are fixed and known, and only y's are random. Recall Ex 3.5.22 in Homework 1. Here the design matrix is 1 T2 and the regression coefficielt is β = (α, β)T, 3. Derive the MLE of a and ß and show that it is independent of σ2· Is your MLE sane as the least square estimation in Ex 3.5.22? 4. Drive the mean...
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
3. Consider the multiple linear regression model where Xii, . .. , Xp-i.i are observed covariate values for observation i, and εί udN(0, σ2) (a) What is the interpretation of in this model? (b) Write the matrix form of the model. Label the response vector, design matrix, coefficient vecto and error vector, and specify the dimensions and elements for each. (c) Write the likelihood, log-likelihood, and 쓿 in matrix form. (d) Solve = 0 for β, the MLE of the...
Decide (with short explanations) whether the following statements are true or false. e) In a simple linear regression model with explanatory variable x and outcome variable y, we have these summary statisties z-10, s/-3 sy-5 and у-20. For a new data point with x = 13, it is possible that the predicted value is y = 26. f A standard multiple regression model with continuous predictors and r2, a categorical predictor T with four values, an interaction between a and...
3. Consider the multiple linear regression model iid where Xi, . . . ,Xp-1 ,i are observed covariate values for observation i, and Ei ~N(0,ơ2) (a) What is the interpretation of B1 in this model? (b) Write the matrix form of the model. Label the response vector, design matrix, coefficient vector, and error vector, and specify the dimensions and elements for each. (c) Write the likelihood, log-likelihood, and in matrix form. aB (d) Solve : 0 for β, the MLE...
1. Consider a GLM (generalised linear model) for a Poisson random sample Y1,. .. , Y, with \Vi each Yi having a pdf or pmf f(y; A;) = i= 1, . .. ,n. Yi = 0, 1,2, -..; ^; > 0; Y;! Note that the pdf from an exponential family has the following general form b(0) + c(y, a(o) y0 exp f(y; 0, 6) = Suppose the linear predictor of the GLM is n = a+Bxi, with (a,B) being the...
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....