click below

click below

Normal Size Small Size show me how

# Statistics Unit 5

### Unit 5 Interval Estimation (Part 1) Estimating a Population Mean

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

A point estimator cannot be expected to provide the exact value of the population parameter. An _____ ______ can be computed by adding and subtracting a _____ __ _______ to the point estimate. | interval estimate , margin of error |

The purpose of an interval estimate is | to provide information about how close the point estimate is to the value of the parameter |

The general form of an interval estimate for an unknown population mean is | y +- Margin of Error |

In order to develop an interval estimate of a population mean, the margin of error must be computed using either: | the population standard deviation Q the sample standard deviation s |

If the population is ________ ________ ________, even very small samples can be used. | approximately normally distributed |

If the population distribution is ______ ________ , a sample size of n=15 is sufficient. | roughly symmetrical |

If the population distribution is _______ ________, a sample size of n=30 is adequate | moderately asymmetric |

If the population distribution is _____ _____ _ ______ _______, a sample size of n=50 is recommended. | highly skewed or contains outliers |

Q unknown case.In this case, | the interval estimate for u is based on the t distribution. |

The t distribution is | a family of similar probability distributions |

A specific t distribution depends on a parameter known as the ____ __ ______ | degrees of freedom. |

Degrees of freedom refer to | the number of independent pieces of information that go into the computation of s. |

As the number of degrees of freedom increases, the difference between the t distribution and the standard normal probability distribution becomes | smaller and smaller. |