31. Appendix B Data Set: Cigarette Tar and Nicotine Refer to Data Set 3 in Appendix B.

a. Use the paired data consisting of tar and nicotine. Based on the result, does there appear to be a linear correlation between cigarette tar and nicotine? If so, can researchers reduce their laboratory expenses by measuring only one of these two variables?

b. Use the paired data consisting of carbon monoxide and nicotine. Based on the result, does there appear to be a linear correlation between cigarette carbon monoxide and nicotine? If so, can researchers reduce their laboratory expenses by measuring only one of these two variables?