Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

Normal Size Small Size show me how

Normal Size Small Size show me how

# Statistics - Exam 3

Question | Answer |
---|---|

Normal distribution with a mean equal to 0 and a standard deviation equal to 1 | standard normal distribution |

Value that serves as a best guess at the value of the population parameter | point estimator |

Range of values used to estimate a population parameter with a specific degree of confidence | confidence interval |

Probability that the interval actually does contain the population parameter | degree of confidence |

value measuring some characteristic of a population | parameter |

complete collection of people, objects, scores, etc. to studied | population |

any sub collection of data drawn from a population | sample |

Characteristics of the standard normal distribution: | 1) central mean, median and mode 2) symmetric 3) curve never touches x axis 4) areas under curve represent probabilities |

Concepts of the Central Limit Theorem: | 1) If random variable x is normally distributed, then the sample mean will be as well for ANY sample size 2) If random variable x is NOT normally distributed then sample mean WILL BE normally distributed if the sample size is large enough (n>30) |

Why use n-1 degrees of freedom? | accounts for error found in small samples |

As sample size increases results __________. | narrow |

As confidence interval increases results ___________. | widen |

Why are interval estimators better than point estimators? | because interval estimators provide an upper and lower boundary increasing the likelihood that the parameter will fall within those bounds |

variance of a sample symbol | s² |

standard deviation of a sample symbol | s |

variance of a population symbol | σ² |

standard deviation of a population symbol | σ |

mean of a sample symbol | x with a line above it |

mean of a population symbol | µ |

proportion of a population symbol | P |

proportion of a sample symbol | p with a hat |

Created by:
K1N1V