Understanding p-values helps test if differences in data ... A more complex test statistic would yield the chi-squared value by adding the squared differences between observed and expected values ...

Paige McLaughlin / Investopedia Chi-square is a statistical measurement that shows how well a model fits the observed data. A chi-square (χ 2) statistic is a test that compares observed data to ...

The chi-square value is calculated using the following formula: Using this formula, the difference between the observed and expected frequencies is calculated for each experimental outcome category.