4. In linear regression modeling, the regression line is sometimes known to go through the origin (0, 0), and x = 0 is within the scope of the model. In such case, we add the assumption that β0 = 0, so the regression model reduces to: Yi = β Xi + εi . (The assumptions about ε remain the same). (Note: Since now there is only one parameter, we simply denote it β instead of β1 ).
(a) Derive the Least-Squares estimator for β , for this model. (Hint: It is different than what we got for the regular model).
(b) Does the property ∑ ei = 0 still hold?
(c) Does the property i i ∑ xi ⋅ei = 0 still hold?
4. In linear regression modeling, the regression line is sometimes known to go through the origin...
1. If a true model of simple linear regression reads: yi −y ̄ = β0 +β1(xi −x ̄)+εi for i = 1, 2, · · · , n, showβ0 =0andβˆ0 =0. (1pt) (hint: use the formula of estimator βˆ0 = y ̄ − βˆ1x ̄.)
We run the following linear regression model in Excel (or any other softwares) Yi = β0 + β1Xi + β2Wi + εi , where i = 1, 2, . . . , 100. The results suggest that the slope on Xi is 97.28 with t-statistics 0.91, and the slope on Wi is 15.81 with t-statistics 11.39. What does it tell us?
#2
can you please go through the steps of how you got this
Consider the simple linear regression model yi-Xißl + β0 + Ei, where the errors €1, €n are i.i.d. random variables with E[c]-0, var(G) σ2, i 1, , n. Solve either one of the questions below. 1. Let h be the least squares estimator for β1- Show that Bi is the best linear unbiased estimator for β1. (Note: you can read the proof in wikipedia, but you cannot...
please show all steps thank
you
4. (10 marks) Let βο and βι be the intercept and slope from the regression of y on xi, using n observations Let c1 and c2, with c#0, be constants. Let ß0 and ßl be the intercept and slope from the regression ofciyi on c2xi. Show that ßi-(c1/c2) B\ and Bo -cißo, thereby verifying the claims on units of measurement in Section 2-4. [Hint: Plug the scaled versions of x and y into A-s....
4. (24 marks) Suppose that the random variables Yi,..., Yn satisfy Y-B BX,+ Ei, 1-1, , n, where βο and βι are parameters, X1, ,X, are con- stants, and e1,... ,en are independent and identically distributed ran- dom variables with Ei ~ N (0,02), where σ2 is a third unknown pa- rameter. This is the familiar form for a simple linear regression model, where the parameters A, β, and σ2 explain the relationship between a dependent (or response) variable Y...
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...
(Do this problem without using R) Consider the simple linear regression model y =β0 + β1x + ε, where the errors are independent and normally distributed, with mean zero and constant variance σ2. Suppose we observe 4 observations x = (1, 1, −1, −1) and y = (5, 3, 4, 0). (a) Fit the simple linear regression model to this data and report the fitted regression line. (b) Carry out a test of hypotheses using α = 0.05 to determine...
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...
4. We have n statistical units. For unit i, we have (xi; yi), for i-1,2,... ,n. We used the least squares line to obtain the estimated regression line у = bo +biz. (a) Show that the centroid (x, y) is a point on the least squares line, where x = (1/n) and у = (1/n) Σ¡ı yi. (Hint: E ) i-1 valuate the line at x = x. (b) In the suggested exercises, we showed that e,-0 and e-0, where...