Welch Two-Sample t Test
Compare two independent sample means without assuming equal variances.
Your numbers
t statistic
For independent samples. Paired measurements require a paired test.
Scenario comparison
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Formula
Use t = (m₁−m₂)/√(s₁²/n₁+s₂²/n₂). m, s and n are each sample's mean, sample standard deviation and size; subscripts distinguish the samples. The two-sided p-value uses Welch–Satterthwaite degrees of freedom, without assuming equal variances.
Compare two independent sample means without assuming equal variances.
Worked example
- Sample A
- 8, 9, 10, 11, 12
- Sample B
- 6, 7, 8, 9, 10
- t statistic
- 2
- Welch degrees of freedom
- 8
- Two-sided p-value
- 0.0805162379573
Scope and limitations
For independent samples. Paired measurements require a paired test.
Inputs are checked for missing values and allowed ranges. A result outside the finite numeric range is not displayed. Rounding affects display, while the calculation uses the model’s numeric precision.
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Formula version: b9e7c9f50fc1 · Example checked: