Question

. Given the following contingency table (using a significance level of 0.05), and assuming the value of the test statistic is 7.135, test for independence between marital status and grade.

A                     B                      C                      D                        F

            DIVORCED    39                   19                   12                   28                   18      

NEVER                       172                 61                        44                   70                   37

Answer 1

Null and alternative hypotheses

Ho : marital status and grade are independent

H1 : marital status and grade are not independent

Here we have chi square test statistic = 7.135

For a = 0.05 and d.f = (r-1)*(c-1) = 1*4 = 4

Chi square critical value = 20.05 , 4

  Chi square critical value = 9.488

Decision rule : it chi square test statistic > critical value if we reject the null hypothesis otherwise not

Our test statistic = 7.135 < 9.488

Decision : we Fail to reject the null hypothesis