# Applied Statistics in Business and Economics, by Doane and Seward: Text Questions. 2)Chapter Exercises 12.48 and 12.50 b. Chapter Exercises 13.30 and 13.32 c.Chapter Exercise 14.16

Essay by kauriUniversity, Bachelor's November 2008

Prepare answers to the following assignments from the e-text, Applied Statistics in Business and Economics, by Doane and Seward:

Chapter 12

Chapter Review #1

Chapter Exercises 12.48 and 12.50

Chapter 13

Chapter Exercises 13.30 and 13.32

Chapter 14

Chapter Exercise 14.16

Chapter 12

Chapter Review #1

List two limitations of bivariate regression.

Often simplistic (multiple relationships usually exist.

Biased estimates, even if relevant predictors are omitted.

Why is estimating a multiple regression model just as easy as bivariate regression?

Because a computer does all the calculations so there is no extra computational burden.

Chapter Exercises:

12.48

In the following regression, X = weekly pay, Y = income tax withheld, and n = 35 McDonald's employees. (a) Write the fitted regression equation. (b) State the degrees of freedom for a two-tailed test for zero slope, and use Appendix D to find the critical value at ÃÂ± = .05. (c) What is your conclusion about the slope? (d) Interpret the 95 percent confidence limits for the slope. (e) Verify that F = t2 for the slope. (f) In your own words, describe the fit of this regression.

R2 0.202

Std. Error 6.816

n 35

ANOVA table

Source SS df MS F p-value

Regression 387.6959 1 387.6959 8.35 .0068

Residual 1,533.0614 33 46.4564

Total 1,920.7573 34

Regression output confidence interval

variables coefficients std. Error t (df = 33) p-value 95% lower 95% upper

Intercept 30.7963 6.4078 4.806 .0000 17.7595 43.8331

Slope 0.0343 0.0119 2.889 .0068 0.0101 0.0584

(a) Write the fitted regression equation.

y = 0.0343x

+ 30.7963

(b) State the degrees of freedom for a two-tailed test for zero slope, and use Appendix D to find the critical value at ÃÂ± = .05.

Dof = 35 - 1 = 34, critical value of t corresponding to 34 dof at (...