T Distribution Test Statistic Formula. T test formula the formula for the two sample t test a k a. Here s p is the pooled standard deviation for n n 1 n 2 and s 2 x 1 and s 2.
In this formula t is the t value x1 and x2 are the means of the two groups being compared s2 is the pooled standard error of the two groups and n1 and n2 are the number of observations in each of the groups. Begin array l qquad t frac bar x 1 bar x 2 s bar delta text where qquad s bar delta sqrt frac s 1 2 n 1 frac s 2 2 n 2 end array. In this formula t is the t value x and x are the means of the two groups being compared s and s are the standard error of the two groups and n and n are the numbers of observations in each of the groups.
The student s t test is shown below.
Determine the degrees of freedom for the t test. The t statistic to test whether the means are different can be calculated as follows. In this formula t is the t value x and x are the means of the two groups being compared s and s are the standard error of the two groups and n and n are the numbers of observations in each of the groups. The exact formula depends on the t test type check the sections dedicated to each particular test for more details.
