Fig. 6

Variation of the most appropriate Student’s t (corresponding to p significance) cut-off value for different sample sizes in each group. The slope of the calculated Student’s t (Eq. 13) is more than the slope of the most appropriate t cut-off value (Eq. 22) so that once the calculated Student’s t (red curve) exceeds the most appropriate t cut-off value (blue curve), it will remain more than that for larger samples