Consider the multivariate multiple regression model
Consider the multivariate multiple regression model nxm)(nxr+ ((1)xm) (nxm) Let the predicted values be Y =...
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. Model assumptions Aa Aa E In a multiple regression model with p independent variables, that is, y-Po + β*1 + assumptions + ßpXp + t, you have the following Assumption 1: The error term ε is a random variable with a mean of zero, that is, E(E)-0 for all values of the independent variables x. Assumption 2: The variance of , denoted by ơ2, is the same for all values of the independent variables xi, X2, , Xp Assumption...
Consider the following formulations of the 1 variable regression model: Y = β0 + β1x + u and Y = α0 + α1(x − ¯x) + a a) would the estimates of β0 and α0 the same? Explicitly shows this by deriving the estimates. b) What about β1 and α1 ? c) In the regression Y = β0 +β1x+u suppose we multiply each X value by a constant, say, 2. Will it change the residuals and fitted values of Y?...
Need help with stats true or false questions
Decide (with short explanations) whether the following statements are true or false a) We consider the model y-Ao +A(z) +E. Let (-0.01, 1.5) be a 95% confidence interval for A In this case, a t-test with significance level 1% rejects the null hypothesis Ho : A-0 against a two sided alternative. b) Complicated models with a lot of parameters are better for prediction then simple models with just a few parameters c)...
1. a. At any given combination of values , the assumptions for the multiple regression model require that the population of potential error term values has? b. What is the point estimate for the constant variance? c.Which of the following is the sum of the squared differences between the predicted values of the dependent variable and the mean of the dependent variable, the explained variation? d.The null hypothesis for the overall F-test states that: At least one ββis not equal...
e. Consider the multiple regression model Y = X1?1 + X2?2 + .
The Gauss-Markov conditions hold. Show that Y0 (I ? H)Y = Y0 (I ?
H1)Y ? ?ˆ0 2X0 2 (I ? H1)Y.
e. Consider the multiple regression model Ý = XiA + X2ß2 + E. The Gauss-Markov conditions hold. show that Y'(l-H)Y-Y'(1-HJY-? (1-H,)Y
3. In the multiple regression model shown in the previous question, which one of the following statements is incorrect: (b) The sum of squared residuals is the square of the length of the vector ü (c) The residual vector is orthogonal to each of the columns of X (d) The square of the length of y is equal to the square of the length of y plus the square of the length of û by the Pythagoras theorem In all...
1. Consider the following simple regression model: y = β0 + β1x1 + u (1) and the following multiple regression model: y = β0 + β1x1 + β2x2 + u (2), where x1 is the variable of primary interest to explain y. Which of the following statements is correct? a. When drawing ceteris paribus conclusions about how x1 affects y, with model (1), we must assume that x2, and all other factors contained in u, are uncorrelated with x1. b....
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 =...
Considering multiple linear regression models, we compute the regression of Y, an n x 1 vector, on an n x (p+1) full rank matrix X. As usual, H = X(XT X)-1 XT is the hat matrix with elements hij at the ith row and jth column. The residual is e; = yi - Ýi. (a) (7 points) Let Y be an n x 1 vector with 1 as its first element and Os elsewhere. Show that the elements of the...