题目
Which of the following statements is correct regarding the chi-squaretest ofindependence?
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\ndegrees of freedom.
答案
A
解析
A is correct. The test statistic comprises squared differences between theobserved 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 categoricalvariables, there are four degrees of freedom.