The Chi-squared test (also known as Chi test) is a statistical test used to determine if there is a significant association between two categorical variables. It compares the observed frequencies in each category with the expected frequencies, assuming that there is no association between the variables.
The Chi-squared test calculates a test statistic (chi-squared statistic) which measures how much the observed frequencies deviate from the expected frequencies. The test statistic follows a chi-squared distribution.
The test can be used for both goodness-of-fit testing, where it compares observed frequencies with expected frequencies in a single variable, as well as for independence testing, where it examines the relationship between two variables.
In practice, the Chi-squared test is often used to analyze survey data, assess the significance of relationships in contingency tables, or test the validity of a model's assumptions.
What is Chi test in statistics
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