1) Given the model y = βο + β1X1 + β2X2 + β3X3 + ε if we plot y against X1 and get a parabola shaped curve then what does this suggest? Choose the correct answer.
a) E(ε) does not equal zero
b) an X12 term is needed
c) an X22 term is needed
d) constant variance violated
Given the model y = βο + β1X1 + β2X2 + β3X3 + ε if we plot y against X1 and get a parabola shaped curve then what does this suggest?
Answer - an X12 term is needed
When estimating y = β0 + β1x1 + β2x2 + β3x3 + ε, you wish to test H0: β1 = β2 = 0 versus HA: At least one βi ≠ 0. The value of the test statistic is F(2,20) = 2.50 and its associated p-value is 0.1073. At the 5% significance level, the conclusion is to ________. Multiple Choice a. reject the null hypothesis; we can conclude that x1 and x2 are jointly significant b. not reject the null hypothesis;...
When estimating y = β0 + β1x1 + β2x2 + β3x3 + ε, you wish to test H0: β1 = β2 = 0 versus HA: At least one βi ≠ 0. The value of the test statistic is F(2,20) = 2.50 and its associated p-value is 0.1073. At the 5% significance level, the conclusion is to ________. Multiple Choice a. reject the null hypothesis; we can conclude that x1 and x2 are jointly significant b. not reject the null hypothesis;...
Consider a regression model Y = β0 + β1X1 + β2X2 + ε, where X1 is a numerical variable, and X2 is a dummy variable. Sketch the response curves (the graphs of E(Y ) as a function of X1 for different values of X2), if η0 = 25, β1 = 0.2, and β2 = −12.
1.The following tables give the results for the full model, as well as a reduced model, containing only experience Test Ho: ß,-Bs-0 vs HA: β2 and/or β3 # 0 Complete Model: Y-βο + β1X1 + β2X2 + β3Xs + ε ANOVA MS P-value df 76.9 Regression Residual Total 2470.4 823.5 224.7 2695.1 .0000 10.7 21 24 Reduced Model: Y = β0 + β X + ε MS df 1 23 24 value 2394.9 2394.9 183.5 0.0000 300.2 13.1 2695.1 Regression...
31. Suppose you fit a multiple linear regression model y = β0 + β1x1 + β2x2 + β3x3 + β4x4 + ε to n = 30 data points and obtain SSE = 282 and R^2 = 0.8266 a.) Find an estimate of s^2 for the multiple regression model (a) s^2 ≈ 30.9856 (b) s^2 ≈ 28.6021 (c) s^2 ≈ 1.3111 (d) s^2 ≈ 29.7938 (d) b.) Based on the data information given in a.), you use F-test to test H0...
Consider the regression model y=β0+β1x1+β2x2+u Suppose this is estimated by Feasible Weighted Least Squares (FWLS) assuming a conditional variance function Varux=σ2h(x). Which of the following statements is correct? A) The function h(x) does not need to be estimated as part of the procedure B) If the assumption about the conditional variance of the error term is incorrect, then FWLS is still consistent. C) FWLS is the best linear unbiased estimator when there is heteroscedasticity. D) None of the above answers...
The following equation was used: ?[?]=?0+?1?1+?2?2+?3?3E[y]=β0+β1x1+β2x2+β3x3 where ?1={10if level 2o.w.x1={1if level 20o.w. ?2={10if level 3o.w.x2={1if level 30o.w. ?3={10if level 4o.w.x3={1if level 40o.w. The model was fitted to n=30 data points, and the following result was obtained: ?̂ =10.2−4?1+12?2+2?3y^=10.2−4x1+12x2+2x3 Use the least squares equation above to find the estimated mean for each level of the qualitative independent variable. Estimated mean for level 1: Estimated mean for level 2: Estimated mean for level 3: Estimated mean for level 4: FOR WEBWORK
1.Given the Multiple Linear regression model as Y-Po + β.X1 + β2X2 + β3Xs + which in matrix notation is written asy-xß +ε where -έ has a N(0,a21) distribution + + ßpXo +ε A. Show that the OLS estimator of the parameter vector B is given by B. Show that the OLS in A above is an unbiased estimator of β Hint: E(β)-β C. Show that the variance of the estimator is Var(B)-o(Xx)-1 D. What is the distribution o the...
Question 2 1 pts suppose you estimate the following model: Y-α + β1 X1 + β2X2 + γΖ + u You wish to test the null hypothesis: Ho; A-:-As against a two-sided alternative. You do so, and get the following estimates: βι 5.23, B2--4.56, 8e (A) 2.09, 8e (%) 1.47, 8e (A-A) 2.24, 8e (A +%)-0.94 What is the value of the relevant test statistic for this hypothesis test? 4.37 0.71 0.30 10.41
2. Suppose Y ~ Exp(a), which has pdf f(y)-1 exp(-y/a). (a) Use the following R code to generate data from the model Yi ~ Exp(0.05/Xi), and provide the scatterplot of Y against X set.seed(123) n <- 500 <-rnorm (n, x 3, 1) Y <- rexp(n, X) (b) Fit the model Yi-Ao + Ax, + ε¡ using the lm function in R and provide a plot of the best fit line on the scatterplot of Y vs X, and the residual...