Tar (C)_{tar}^{ISO} | Nicotine (C)_{nic}^{ISO} | CO (C)_{co}^{ISO} | |
---|---|---|---|

C, concentration; ISO, International Organization for Standardization; N^{ISO}, number of puffs; S, paper porosity; V filter ventilation; W, weight of tobacco filter.^{f} | |||

Note that filter ventilation (V) is introduced in step 1 as the first (most important) explanatory variable, with very high R^{f}^{2} values for all three emissions. Values of F and associated degrees of freedom (df) as well as the regression coefficients are given for each model. | |||

Step 1 variable |
V
^{f} |
V
^{f} |
V
^{f} |

R^{2} | 0.903 | 0.853 | 0.892 |

Step 2 variable |
N
^{ISO} |
N
^{ISO} | W |

R^{2} | 0.933 | 0.940 | 0.942 |

Step 3 variable | S | ||

R^{2} | 0.951 | ||

Model intercept | 8.560 | 0.346 | 7.142 |

β1 | −0.174V^{f} | −0.012V^{f} | −0.133V^{f} |

β2 | 0.799N^{ISO} | 0.095N^{ISO} | 10.128W |

β3 | −0.022S | ||

F (df) | 321.8 (2, 46) | 358.8 (2, 46) | 292.9 (3, 45) |