T Test Test Statistic Formula. 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. X 1 x 2 s p 1 n 1 1 n 2 where x 1 and x 2 are the sample means n 1 and n 2 are the sample sizes and where s p is calculated as.
Standard deviation of first set of values. S p n 1 1 s 1 2 n 2 1 s 2 2 n 1 n 2 2 where s 1 2 and s 2 2 are the sample variances. Mean of second set of values.
Once we have the t value we have to look at the t tables.
Once we have the t value we have to look at the t tables. S p n 1 1 s 1 2 n 2 1 s 2 2 n 1 n 2 2 where s 1 2 and s 2 2 are the sample variances. The t score formula for the welch t test is. T test formula the formula for the two sample t test a k a.
