Number of centerline reflectors per half kilometer |
---|

84 |

74 |

78 |

61 |

67 |

55 |

54 |

62 |

61 |

83 |

81 |

75 |

70 |

65 |

70 |

76 |

The number of new orange centerline reflectors from the Sokeh's Island junction to the college in Palikir was counted by a three person team. The numbers are the number of markers for each half kilometer.

- _________ Calculate the sample size
**n**. - _________ Calculate the sample mean
**x**. - _________ Calculate the sample standard deviation
**sx**. - _________ What is the point estimate for the population mean μ?
- _________ Calculate the standard error SE.
- _________ Calculate the number of degrees of freedom.
- _________ Calculate t-critical t
_{c}for a confidence level c of 95% (0.95) - _________ Calculate the margin of error E.
- Calculate the 95% confidence interval for the population mean μ

p(__________ ≤ μ ≤ __________) = 0.95

Confidence interval statistics | |||
---|---|---|---|

Statistic or Parameter | Symbol | Equations | OpenOffice |

Degrees of freedom | df | n − 1 | =COUNT(data)-1 |

Find a t_{critical} value from a confidence level c |
t_{c} | =TINV(1-c;df) | |

Standard error of the sample mean | SE | =STDEV(data)/SQRT(sample size n) | |

Calculate a margin of error for the mean E for n ≥ 5 using sx. | E | =t_{c}*sx/SQRT(n) | |

Calculate a confidence interval for a population mean μ from a sample mean x and an error tolerance E | x − E ≤ μ ≤ x + E |