Standardized Test Statistic Calculator
| Test Type | Result | Date |
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Formula
Z-test: (X̄ - μ) / (σ/√n)
T-test: (X̄ - μ) / (s/√n)
Frequently Asked Questions
What is a standardized test statistic?
A standardized test statistic measures how many standard deviations a data point is from the population mean. It's used in hypothesis testing to determine statistical significance. Common types include z-scores and t-scores, which help researchers compare sample data to population parameters while accounting for sample size and variability.
When should I use z-test vs t-test?
Use z-test when population standard deviation is known and sample size > 30. Use t-test for smaller samples or when population standard deviation is unknown. The t-test accounts for more variability in small samples through degrees of freedom, providing more conservative estimates than z-tests.