Final answer:
For a chi-square test, a contingency table with 3 rows and 4 columns has 6 degrees of freedom, calculated by multiplying the number of rows minus one by the number of columns minus one.
Step-by-step explanation:
For a chi-square test, a contingency table with 3 rows and 4 columns would have degrees of freedom calculated by subtracting one from the number of rows and columns and then multiplying the two results together. Therefore, the degrees of freedom (df) would be given by:
df = (number of rows - 1) × (number of columns - 1)
df = (3 - 1) × (4 - 1)
df = 2 × 3
df = 6
The degrees of freedom determine which chi-square distribution is used for the analysis of the contingency table. It is essential for the correct interpretation of the p-value in hypothesis testing of whether two categorical variables are independent.