Chi-Square Calculator
Calculate the chi-square statistic for goodness-of-fit with three observed and expected frequency pairs.
How to Use the Chi-Square Calculator
- Enter observed and expected frequencies for three categories.
- Click Calculate to get the χ² statistic.
- Compare with the critical value to assess significance.
Referência Rápida
| De | Para |
|---|---|
| df=1, α=0.05 | χ² crit = 3.841 |
| df=2, α=0.05 | χ² crit = 5.991 |
| df=3, α=0.05 | χ² crit = 7.815 |
| df=5, α=0.05 | χ² crit = 11.070 |
| χ² > crit | Reject H₀ |
Casos de Uso
- •Testing whether observed data fits an expected distribution.
- •Analyzing survey responses against expected proportions.
- •Quality control comparisons against theoretical distributions.
Fórmula
χ² = Σ(Oᵢ − Eᵢ)² / Eᵢ. Degrees of freedom = k − 1. Compare with critical value at α = 0.05.
Perguntas Frequentes
What is the chi-square test?
A test that compares observed frequencies with expected frequencies to determine if differences are statistically significant.
What are degrees of freedom?
For goodness-of-fit, df = number of categories minus 1.
How do I interpret the result?
If χ² > critical value at your significance level, reject the null hypothesis.