Feedback: The equation ŷ = β0
̂+ β1
̂x denotes the sample regression function of the given regression
model.
7. Consider the following regression model: y = β0 + β1x1 + u. Which of the following is a property of
Ordinary Least Square (OLS) estimates of this model and their associated statistics?
a. The sum, and therefore the sample average of the OLS residuals, is positive.
b. The sum of the OLS residuals is negative.
c. The sample covariance between the regressors and the OLS residuals is positive.
d. The point (x̅, y̅) always lies on the OLS regression line.
8. The explained sum of squares for the regression function, yi= β0+ β1x1+ u1, is defined as _____.
a. ∑(𝑦𝑖− 𝑦̅)2
𝑛
𝑖=1
b. ∑(𝑦𝑖− 𝑦̂)2
𝑛
𝑖=1
c. ∑𝑢𝑖
̂
𝑛
𝑖=1
d.∑(𝑢𝑖)2
𝑛
𝑖=1
9. If the total sum of squares (SST) in a regression equation is 81, and the residual sum of squares (SSR) is
25, what is the explained sum of squares (SSE)?
a. 64
b. 56
c. 32
d. 18