A chi-square test for independence is used to evaluate the relationship between two variables. If both variables are classified into two categories, then what is the df value for the chi-square statistic?

df = (r - 1) * (c - 1)

Step-by-step explanation:

Chi square is calculated when simple random sampling is known and variable are categorical.

Four steps are included in chi-square:

(1) state the hypotheses

(2) formulate an analysis plan

(3) analyze sample data

(4) interpret results.

State the hypothesis is

null hypothesis: Variable a and variable b are independent.

H 1: Variable a and variable bare not independent.

Formulate analysis plan:

This plan describe the significance level and test statistic.

Analyze the sample data

We analyze the degree of freedom and expected frequencies.

The degree of freedom formula is

df = (r - 1) * (c - 1)

r = number of levels for one categorical variable

c = number of levels for the other categorical variable