the level of significance

问题如下：

In the step "stating a decision rule" in testing a hypothesis, which of the following elements must be specified?

选项：

A.

Critical value

B.

Power of a test

C.

Value of a test statistic

解释：

A is correct.

The critical value in a decision rule is the rejection point for the test. It is the point with which the test statistic is compared to determine whether to reject the null hypothesis, which is part of the fourth step in hypothesis testing.

这道题目有一个背景即：题干中的In the step "stating a decision rule" ，也就是在 "stating a decision rule" （判断是否拒绝原假设）这一步需要确定的是什么。

这一步要确定的是critical value。这是一个比较机械的结论，需要同学记忆。