This module provides a summary on formulas used in Chi-Square Distribution as a part of Collaborative Statistics collection (col10522) by Barbara Illowsky and Susan Dean.
Test of independence
- Use the test of independence to test whether two factors are
independent or not.
- The degrees of freedom are equal to
.
- The test statistic is
where
= observed values,
= expected values,
= the number of rows in the
table, and
= the number of columns in
the table.
- The test is right-tailed.
- If the null hypothesis is true, the expected number
.
The expected value for each cell needs to be at least 5 in order to
use the Independence test.
Glossary
Contingency table
The method of displaying a frequency distribution as a table with rows and columns to show how two variables may be dependent (contingent) upon each other. The table provides an easy way to calculate conditional probabilities
