Chapter 14

Question 1

What is the regression formula with two independent variables

Answer 1

yhat= a+bx1+bx2

Question 2

The square root of SSE/n-(K+1), also the square root of MSE

Answer 2

Multiple standard error of estimate

Question 3

The percent of variation in the dependent variable y, explained by the set of independent variables

Answer 3

Coefficient of multiple determination

Question 4

Characteristics of Coefficient of Multiple Determination

Answer 4

1. Capital R
2. Ranges from 0 to 1
3. It cannot assume negative values
4. It is easy to interpret

Question 5

What does SSR/SST give you

Answer 5

Coefficient of multiple determination

Question 6

This test investigates whether it is possible that all the independent variables have zero regression coefficients

Answer 6

Global test

Question 7

What are the 5 characteristics of a global test

Answer 7

1. Based on family of F-distributions
2. F distribution cannot be negative
3. It is a continuous distribution
4. Positively skewed
5. It is asymptotic

Question 8

What df should be used when doing individual t test for the independent variables

Answer 8

The residual df

Question 9

How should the standard error be interpreted for a regression model

Answer 9

It is the typical “error” when the regression equation is used to predict Y

Question 10

What are the 5 assumptions of a for a multiple regression test

Answer 10

1. There is a linear relationship
2. The variation in the residuals is the same for both large and small values of yhat
3. The residuals follow the normal probability distribution
4. The independent variables should not be correlated
5. The residuals are in independent

Question 11

What happens to if the number of variables in a multiple regression is equal to the sample size

Answer 11

The coefficient of determination becomes 1

Question 12

Term for The variation around the regression equation is the same for all of the values of the independent variables

Answer 12

Homoscedasticity

Question 13

Term for events where independent variables are correlated

Answer 13

multicollinearity

Question 14

When successive residuals are correlated. Residuals will cluster mostly positive on the left and negative on the right

Answer 14

autocorrelation

Question 15

A variable in which there are only two possible outcomes. For analysis, one of the outcomes is coded a 1 and the other a 0

Answer 15

Dummy variable

Question 16

How do you produce a third independent variable for interaction

Answer 16

Multiply x1 by x2

Question 17

A step by step method to determine a regression equation that begins with a single independent variable and adds or deletes independent variables one by one.

Answer 17

Stepwise regression

Question 18

What type of variables are included in stepwise regression

Answer 18

Independent variables with non zero coefficients are included in the final regression equation