# With the addition of five pairs of observations(18,000, 39.2), (22,400, 27.9), (24,210, 22.3), (5,400, 11.7), and (9,340,

## Question:

a. Using the accompanying computer output, complete the following ANOVA table for the straight-line regression of TIME (Y) on INC (X).

b. Using the accompanying computer output, complete the following ANOVA table for the quadratic regression of TIME (Y) on INC (X).

c. On the scatter diagram of the data for this problem, plot the fitted straight-line (degree 1) equation and the fitted quadratic (degree 2) equation.

d. Calculate and compare the R2-values obtained for the straight-line, quadratic, and cubic fits.

e. Carry out F tests for the significance of the straight-line regression and for the adequacy of fit of the straight-line model.

f. Carry out F tests for the significance of the quadratic regression, of the addition of the quadratic term to the model, and of the adequacy of fit of the quadratic model.

g. Which model is most appropriate: straight-line, quadratic, or cubic?

Linear regression of TIME (Y) on INC (X)

Quadratic regression of TIME (Y) on INC (X)

Cubic regression of TIME (Y) on INC (X)

Regression of TIME (Y) on INC (X)

## Step by Step Answer:

**Related Book For**

## Applied Regression Analysis and Other Multivariable Methods

**ISBN:** 978-1285051086

5th edition

**Authors:** David G. Kleinbaum, Lawrence L. Kupper, Azhar Nizam, Eli S. Rosenberg