Two-Sample T-Test
Statistics & ProbabilityPerform independent two-sample t-tests (Student's t-test with pooled variance and Welch's t-test for unequal variances) to compare population sample means and statistical significance.
Two-tailed p = 0.00692 (df = 14)
About this calculator
Comparing two experimental groups (e.g. medical treatment vs control, or website variation A vs variation B) requires testing whether difference in sample means is statistically significant or merely sampling noise.
This calculator performs both standard pooled-variance Student's t-tests (when group variances are equal) and Welch's t-tests (when variances or sample sizes differ), outputting the t-statistic, degrees of freedom, and p-value.
How It Works & Formula
t = (x̄₁ - x̄₂) / √(s₁²/n₁ + s₂²/n₂). Welch–Satterthwaite equation computes effective degrees of freedom. The two-tailed p-value is evaluated against the Student t-distribution CDF.
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