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 ÃÂ± = .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 ÃÂ± = .05.**

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