The same formula and logic applies to studies involving siblings or research on husbands and wives in the same family. Observations are sampled from normal populations. Observe histograms for each group. Homogeneity of Variance.
Samples come from populations with equal variances.
Checked using F-max test which in turn is sensative to nonnormality. The Trick to the Dependent t-test Compute the difference between the two scores. Use the single sample t-test formula. Formulas Standart Deviation for the Differences Dependent t-test Example Consider these hypothetical scores for husbands and wives regarding their attitudes towards bilingual education. Obs Mean Std.