Determining Normality. In Exercises 9–12, refer to the indicated sample data and determine whether they appear to be from a population with a normal distribution. Assume that this requirement is loose in the sense that the population distribution need not be exactly normal, but it must be a distribution that is roughly bell-shaped.

Flight Arrival Delays The arrival delay times (minutes) as listed in Data Set 15 in Appendix B.

Answer :

Step 1 of 1 :

Given, The arrival delay times

class |
arv delay |

-60 - -40 |
1 |

-40 - -20 |
19 |

-20 - 0 |
18 |

0 - 20 |
8 |

20 - 40 |
1 |

40 - 60 |
1 |

60 - 80 |
0 |

80 - 100 |
0 |

100 - 120 |
1 |

120 - 140 |
1 |

If the histogram is roughly bell shaped, then the distribution is normal.

The given distribution is not normal.