统计学五参数估计.pptVIP

90 90 As a result of this class, you will be able to ... 38 In this diagram, do the populations have equal or unequal variances? Unequal. 90 38 In this diagram, do the populations have equal or unequal variances? Unequal. 解： 必要样本容量的影响因素 总体方差的大小； 允许误差范围的大小； 概率保证程度； 抽样方法； 抽样的组织方式。 重复抽样条件下： 不重复抽样条件下： 抽样复查的方法 其全面调查时的登记结果为2.2861亿元 其抽样复查的结果为2.1734亿元 随机抽取 五个下属单位 修正系数为 则： 该企业集团所拥有的固定资产原值应为 16.851×0.9507=16.020（亿元） 所拥有固定资产 原值的普查结果为 16.851亿元 某企业集团 总体 * * * * * * * 这个图需要做出说明：所有可能抽样的样本平均数距离mu~的远近可以用方差来刻画；这两次抽样的平均误差哪个大就容易做出判断了。 An estimator is a random variable used to estimate a population parameter (characteristic). Unbiasedness An estimator is unbiased if the mean of its sampling distribution is equal to the population parameter. Efficiency The efficiency of an unbiased estimator is measured by the variance of its sampling distribution. If two estimators, with the same sample size, are both unbiased, then the one with the smaller variance has greater relative efficiency. Consistency An estimator is a consistent estimator of a population parameter if the larger the sample size, the more likely it is that the estimate will come close to the parameter. An estimator is a random variable used to estimate a population parameter (characteristic). Unbiasedness An estimator is unbiased if the mean of its sampling distribution is equal to the population parameter. Efficiency The efficiency of an unbiased estimator is measured by the variance of its sampling distribution. If two estimators, with the same sample size, are both unbiased, then the one with the smaller variance has greater relative efficiency. Consistency An estimator is a consistent estimator of a population parameter if the larger the sample size, the more likely it is that the estimate will come close to the parameter. An estimator is a random variable used to estimate a population parameter (characteristic). Unbiasedness An estimator is unbiased if the mean of its sampling distri