3. (a) In a least squares regression of y on x, observations for which x is far from its mean will have more effect on the estimated slope than observations for which x is close to its mean value....

Extracted text: 3. (a) In a least squares regression of y on x, observations for which x is far from its mean will have more effect on the estimated slope than observations for which x is close to its mean value. Indicate whether the statement is true, false, or uncertain, and give a brief explanation. (b) Briefly discuss the Breusch and Pagan's test for “heteroskedasticity". (d) Discuss "Dummy variable trap" with an example.