T Test Formula Explained. The null hypothesis h 0 and alternative hypothesis h 1 of the independent samples t test can be expressed in two different but equivalent ways h 0. Mean 1 and mean 2 the average values of each of the sample sets s diff the standard deviation of the differences of the paired data values n.
µ 1 µ 2 the two population means are equal h 1. T 1 11 means that our difference of 7 minutes is roughly 1 standard deviation below the average of zero. The t score formula for the welch t test is.
Mathematically it is represented as t x 1 x 2 s21 n 1 s22 n 2.
T is basically the standardized sample mean difference. The null hypothesis h 0 and alternative hypothesis h 1 of the independent samples t test can be expressed in two different but equivalent ways h 0. Independent two sample t test. Df n 1 n 2 2 we subtract 2 because each of the two means we computed costs us one degree of freedom.
