Refer to the asphalt data in Example 1.12 (page 18).

a. Construct a boxplot for the asphalt data.

b. Which values, if any, are outliers?

c. Construct a dotplot for the asphalt data.

d. For purposes of constructing boxplots, an outlier is defined to be a point whose distance from the nearest quartile is more than 1.5 IQR. A more general, and less precise, definition is that in outlier is any point that is detached from the bulk of the data. Are there any points in the asphalt data set that are outliers under this more general definition, but not under the boxplot definition? If so, which are they?

Answer:

Step 1 of 5:

The given values of fracture stress (in megapascals) were measured for a sample of 24 mixtures of hot-mixed asphalt (HMA). The values are tabulated below.

30 |

75 |

79 |

80 |

80 |

105 |

126 |

138 |

149 |

179 |

179 |

191 |

223 |

232 |

232 |

236 |

240 |

242 |

245 |

247 |

254 |

274 |

384 |

470 |