Hypothesis Test Calculator (T-Test, Z-Test)

Hypothesis testing is a statistical method to determine whether the difference between a sample or two samples is due to chance or is real. H₀ (null hypothesis) = no difference, H₁ (alternative hypothesis) = there is a difference. T-Test vs Z-Test difference: T-test is used when sample is small (typically n<30) or population standard deviation is unknown. Z-test is used for large samples or when population standard deviation is known. Reject H₀ if p-value < α (difference is significant). Applications and examples: Testing drug effectiveness (new drug → old drug comparison), marketing campaign evaluation (pre → post campaign sales), educational research (comparing different teaching methods), quality control (compliance with production standards).