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

Table 2.

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

Pattern Tribe Obs. population (n) Sampled population (N) Obs. proportion z-value (calculated) |z| critical P value (obs.) Inference
Wavy Ikwerre 117 289 0.405 −4.7572 1.96 <0.0001 Significant difference in proportions
Igbo 188 314 0.599

Curvy Ikwerre 99 289 0.343 2.1791 1.96 0.02926 Significant difference in proportions
Igbo 82 314 0.261

Circular Ikwerre 14 289 0.048 −0.9672 1.96 0.33204 No significant difference in proportions
Igbo 21 314 0.067

Straight Ikwerre 34 289 0.118 3.1373 1.96 0.00168 Significant difference in proportions
Igbo 15 314 0.048

Converging Ikwerre 7 289 0.024 0.7289 1.96 0.4654 No significant difference in proportions
Igbo 5 314 0.016

Diverging Ikwerre 18 289 0.062 3.5282 1.96 0.00042 Significant difference in proportions
Igbo 3 314 0.01

The asterisks were used to demonstrate values with significant difference.