Consider the bivariate linear regression model given by  

Let  denote the OLS estimator of  in (1). 

If the sample variance of is 5 and the sample covariance between and is 100, which of the following statements is correct?

We have estimated the model experience using OLS based on a sample of 4 observations. We know that the matrix of explanatory variables is and we are told that the OLS residuals are: We can immediately say that the residual vector:

Let Which one of the following matrices is ? (Hint: You do not need to know how to calculate an inverse of a matrix, you only need to check which of the following satisfies the definition of an inverse.)

Suppose that when the bivariate linear regression model in the previous question is estimated by OLS, and . Which of the following statements is correct?

Let 

.

Which of the following statements is correct?

Let 

, .

Which of the following statements is correct?

Let 

.

Which of the following statements is correct?

Let 

, .

Which of the following statements is correct?

Let 

, .

Which of the following statements is correct?