2-Sample t

The 2-Sample t conducts a hypothesis test of the difference between two population means when the population standard deviation, s is unknown. It also calculates a confidence interval of the mean. This procedure is based on the t-distribution which is derived from a normal distribution. The samples should be drawn independently from each other. For dependent samples, use the Paired t-test.

Test Null Hypothesis, H0 Alternate Hypothesis, H1
One-tailed μ1 - μ2 = 0 μ1 - μ2 < d or μ1 - μ2 > d
Two-tailed μ1 - μ2 = 0 μ1 - μ2 ≠ 0

where μ1 and μ2 are the population means and d is the hypothesised difference between the population means.