T-Score (T-Test) Calculator
Calculate t-values, degrees of freedom, and p-values for one-sample, two-sample, and paired t-tests.
T-Score (t-value)
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Test Statistics
| Degrees of Freedom (df): | - |
| Standard Error (SE): | - |
| Effect Size (Cohen's d): | - |
P-Values
| Two-Tailed p-value: | - |
| Left-Tailed p-value: | - |
| Right-Tailed p-value: | - |
Interpretation
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Step-by-Step Calculation
Select a test type and enter your data, then click "Calculate T-Score" to see the step-by-step solution.
T-Test Formulas
- One-Sample: t = (x̄ - μ) / (s / √n)
- Two-Sample (Pooled): t = (x̄₁ - x̄₂) / (s_p · √(1/n₁ + 1/n₂))
- Two-Sample (Welch): t = (x̄₁ - x̄₂) / √(s₁²/n₁ + s₂²/n₂)
- Paired: t = d̄ / (s_d / √n)
Degrees of Freedom
- One-Sample: df = n - 1
- Two-Sample (Pooled): df = n₁ + n₂ - 2
- Two-Sample (Welch): df = (s₁²/n₁ + s₂²/n₂)² / [ (s₁²/n₁)²/(n₁-1) + (s₂²/n₂)²/(n₂-1) ]
- Paired: df = n - 1
When to Use
- One-Sample: Compare sample mean to known population mean
- Two-Sample: Compare means of two independent groups
- Paired: Compare means of two related groups (before/after)