Perform a one-sample or two-sample t-test with t statistic, degrees of freedom and p-value.
The t-test determines whether a sample mean (or the difference between two sample means) is statistically significantly different from a hypothesised value. This calculator uses Welch's t-test for two samples, which does not assume equal variances.
One-sample t
t = (x̄ − μ₀) / (s / √n)
Two-sample t (Welch)
t = (x̄₁ − x̄₂) / √(s₁²/n₁ + s₂²/n₂)
Use one-sample when testing if a single group's mean equals a known value. Use two-sample when comparing the means of two independent groups.
Welch's t-test is a modification of the two-sample t-test that does not assume equal variances between the two groups, making it more generally applicable.