这是本文档旧的修订版！

第五章：样本均值的分布、假设检验初步

Chapter 5: Distribution of Sample Means and Preliminary Hypothesis Testing

本章概览 (Guide)：

在前面几讲的学习中，我们研究的是总体或者总体中抽取的单独一个样本。而在实际的研究中，我们抽取的样本远远不止三个。在本章，我们将所有这些可抽取的样本构成一个集合，学习它们之间、它们与总体之间的关系。此外，我们还将初步了解假设检验的程序和两类错误。
In the previous lectures, we studied a whole population or a single sample extracted from the population. In real research, we need to extract far more than three samples. In this chapter, we will form a set of all these extractable samples and learn their relationships with each other and with the population. In addition, we will also have a preliminary understanding of the hypothesis testing procedure and two types of errors.

学习要点 (Laerning Points)：

掌握样本均值分布的特性（形状、均值、标准误）
Master the characteristics of sample mean distribution (shape, mean, standard error)
区分标准误、标准差和取样误差
Distinguish standard error, standard deviation, and sampling error
学会利用中心极限定律求解标准误
Learn how to use the central limit law to calculate standard errors
学会计算样本均值分布中的概率
Learn how to calculate the probability in the sample mean distribution
掌握假设检验的基本步骤
Master the basic steps of hypothesis testing
学会分辨假设检验的两类错误
Learn how to distinguish two types of errors in hypothesis testing

作业