Question 1. [Total Marks: 20]
Given the following information on dependent variable Y and two independent variables X2
and X3:
Number of observations, n=15.
Y- = 1942.33, -X2 = 2126.33, X- 3 = 8.0, IC~- Y-2) = 830121.33,
xx= l 15
[
31895
120
31895
68922.513
272144
120
272144
1240
l ky =
29135
[ 62905821
247934
37.2324 -0.0225
l (xX)-
1=
[
-0.0225
1.3367
0.00001
-0.0008
1.3367
-0.0008
0.0540
y'y = 57,420
p Residual Sum of Squares (RSS),I u/ = y'y- Xy =1976.8557
Explained Sum of Squares (ESS)=828144.4778
Total Sum of Squares (TSS)= 830121.333
Answer the following questions:
(a) Find p.
(b) Fit the regression model of Yon X2and X3.
(c) Find R2 .
(d) Develop ANOVA table and test the hypothesis H0 : {32 = {33 = 0.
(6 marks)
(4 marks)
(4marks)
(6 marks)
Question 2. [Total Marks: 20]
(a) Prove that in a classical linear regression model, OLSestimators have minimum variance.
(10 marks)
(b) How can the problem of heteroskedasticity be removed by the method of generalized
least squares?
(10 marks)
Question 3. [Total Marks: 20]
(a) Discuss the estimation of parameters of a regression model in presence of perfect
multicollinearity.
(10 marks)
(b) Using matrix approach, prove that in a multiple regression model, the OLSestimators are
unbiased.
(10 marks)
2