Econ quiz 2.1

Question 1

var(X) should always be (positive/negative)?

Answer 1

Positive

Question 2

If all the X values are identical, then Xi = ?

Answer 2

Xi = x̄

Question 3

Why are assumptions important?

Answer 3

Because predictions based on those assumptions are usuful

Question 4

What would it mean if all observations were to lie on the regression line?

Answer 4

We would have a perfect fit line (rare)

Question 5

What is the goal of obtaining residuals?

Answer 5

Help determining the regression line while minimizing the spread around the perfect fit line.

Question 6

What is the coefficient of determination as a var?

Answer 6

r^2 (summary measure that tells how well the sample regression line fits the data

Question 7

TSS?

Answer 7

Total sum of squares

Question 8

ESS?

Answer 8

Explained sum of squares

Question 9

RSS

Answer 9

residual sum of squares

Question 10

What does r^2 measure

Answer 10

the proportion of the totla variation in Y explained by the regression model

Question 11

Is r^2 <1 or >1

Answer 11

r^2 is 0<r^2<1

Question 12

PRF?

Answer 12

Population Regression Function

Question 13

Another objective of regression analysis is to obtain…

Answer 13

infernces about the popoulation regression fuction (PRF)

Question 14

What are some OLS properties

Answer 14

1. unbiased
2. minimal variance
3. consistency

Question 15

What is Efficiency in terms of var

Answer 15

refers to t var of the estimators sampling distribution