TRUE or FALSE and Explain why:
In a multiple regression model, the inclusion of a variable
Answering only the first question:
1) TRUE. Inclusion of an additional variable can reduce the risk of omitted variable bias in your multiple regression. But, such variables do not contribute much to the explanatory power of the model. So, the estimators of the other variables are not effected much. These variables tend to reduce the degrees of freedom.
Also take for example, include a third irrelevant variable X3 into the model with a coefficient zero. Although the estimators will still be consistent but, if the variables X2 and X3 are correlated somehow, then the correlation coefficient may lead to an increased variance of the estimator. Hence, reducing the efficiency of the model.
TRUE or FALSE and Explain why: In a multiple regression model, the inclusion of a variable
TRUE or FALSE and Explain why: If the error term in a simple regression model is heteroskedastic, the estimated OLS coefficients are biased.
Section 1: True/False, & explain why three or more sentences: 2. In the regression model Yi = β0 + β1Xi + β2Di + β3(Xi × Di) + ui, where X is a continuous variable and D is a binary variable, β3 has no meaning since (Xi×Di) = 0 when Di= 0.
12. (Ch13.5) True or False? The effect of a binary predictor in a multiple regression with three predictors (two of them are continuous, one is binary) is to shift the regression fitting plane up or down 13. (Ch13.5) True or False? Unlike other predictors, the student's t for testing the significance of a binary predictor is either 0 or l1 14. (Ch13.5) In a multiple regression model of student grades, we would code the nine categories of business courses taken...
Question 5 (1 point) The multiple regression model includes several dependent variables. True False Question 6 (1 point) Dummy variables for regression analysis can take on a value of either -1 or +1. True False Question 7 (1 point) The several criteria (maximax, maximin, equally likely, criterion of realism, minimax regret) used for decision making under uncertainty may lead to the choice of different alternatives. True False Question 8 (1 point)
A regression model that is linear in the unknown parameters is a linear regression model. A) True B) False The test for significance of regression in multiple regression involves testing the hypotheses Ho: B1=B2=B3=0 versus H1: B1≠B2≠B3≠0. A) True B) False The ANOVA is used to test for significance of regression in multiple regression. A) True B) False
TRUE or FALSE Please explain why. Regression techniques can be used to obtain the sample correlation coefficient.
Question 3. Multiple linear regression [6 marks] Create a multiple linear regression model, including as explanatory variables wt, am and qsec. To run multiple linear regression to predict variable A based on variables B, C and D you need to use R’s linear model command, Im as follows, storing the results in an object I'll call regm. regm <- lm (A B + C + D) summary(regm) Report the output from the relevant summary() command. Explain why the R2 and...
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...
In multiple regression, the intercept must be tested to determine if it is significant. True False The interpolation forecast represents a forecast using the actual data from which the regression equation was computed. True False
1.13 Consider a multiple regression model 1.15 Consider a multiple regression model: with a dummy variable: h(wage)-A, + β.educ + β white + β,NonWhite + u where wage and educ denote the annual income and the number of years of education, respectively. White indicates the dummy variable taking 1 if white and zero otherwisc. Non White indicates the dummy variable taking 1 if non-white (African, Hispanic, Asian, Pacific Islander, Native American, etc.) and zero otherwise. Which of the following is...