13. Appendix B Data Set: Predicting Nicotine in Cigarettes Refer to Data Set 3 in Appendix B.

a. Find the regression equation that expresses the response variable (y) of nicotine amount in terms of the predictor variable (x) of the tar amount.

b. Find the regression equation that expresses the response variable (y) of nicotine amount in terms of the predictor variable (x) of the carbon monoxide amount.

c. Find the regression equation that expresses the response variable (y) of nicotine amount in terms of predictor variables (x) of tar amount and carbon monoxide amount.

d. For the regression equations found in parts (a), (b), and (c), which is the best equation for predicting the nicotine amount?

e. Is the best regression equation identified in part

(d) a good equation for predicting the nicotine amount? Why or why not?