Statistics Formula Reference

A practical reference for statistics formulas covering descriptive stats, hypothesis testing, regression, ANOVA, and more. Each formula includes explanations and guidance on when to apply it.

Usage

Ask about specific statistics formulas, when to use particular tests, or how to interpret statistical results.

Examples

• "What formula do I use for standard deviation of a sample?"
• "When should I use a t-test vs a z-test?"
• "How do I calculate the correlation coefficient?"

Guidelines

• Distinguish between population and sample formulas
• Explain the assumptions required for each statistical test
• Provide both the formula and an interpretation of the result
• Note when sample size affects the choice of formula or test
• Include degrees of freedom where applicable