NO.PZ2022123001000128
问题如下：
Which of the following statements is correct regarding the chi-square test of independence?
选项：
A.The test has a one-sided rejection region B.The null hypothesis is that the two groups are dependent C.If there are two categories, each with three levels or groups, there are six degrees of freedom.解释：
The test statistic comprises squared differences between the observed and expected values, so the test involves only one side, the right side. B is incorrect because the null hypothesis is that the groups are independent, and C is incorrect because with three levels of groups for the two categorical variables, there are four degrees of freedom.
1.卡方检验只有图中圈的这一个是吗？
2.怎么判断卡方检验有几个side的rejection region?
3.只有卡方检验的df=(r-1)(c-1)是吗？
