. 2014 Sep 8;2014:123925. doi: 10.1155/2014/123925

Table 1.

Z-test of proportionality difference in rugae pattern distribution between Ikwerre and Igbo males.

Pattern	Tribe	Obs. population (n)	Sampled population (N)	Obs. proportion	z-value (calculated)	\|z\| critical	P value (obs.)	Inference
Wavy	Ikwerre	119	335	0.356	−3.98	1.96	<0.0001	Significant difference in proportions ∗
Wavy	Igbo	161	312	0.511	−3.98	1.96	<0.0001	Significant difference in proportions ∗

Curvy	Ikwerre	151	335	0.451	4.53	1.96	<0.0001	Significant difference in proportions ∗
Curvy	Igbo	87	312	0.279	4.53	1.96	<0.0001	Significant difference in proportions ∗

Circular	Ikwerre	12	335	0.036	−1.49	1.96	0.136	No significant difference in proportions
Circular	Igbo	19	312	0.061	−1.49	1.96	0.136	No significant difference in proportions

Straight	Ikwerre	33	335	0.099	1.76	1.96	0.078	No significant difference in proportions
Straight	Igbo	19	312	0.061	1.76	1.96	0.078	No significant difference in proportions

Converging	Ikwerre	7	335	0.021	−0.89	1.96	0.373	No significant difference in proportions
Converging	Igbo	10	312	0.032	−0.89	1.96	0.373	No significant difference in proportions

Diverging	Ikwerre	13	335	0.039	−0.77	1.96	0.441	No significant difference in proportions
Diverging	Igbo	16	312	0.051	−0.77	1.96	0.441	No significant difference in proportions

The asterisks were used to demonstrate values with significant difference.