. 2021 May 13;7(5):e06988. doi: 10.1016/j.heliyon.2021.e06988

Table 3.

Kruskal-Wallis H test analysis of the variation of elemental concentrations between tap water samples from Gullele and Akaki-Kality Sub-Cities of Addis Ababa.

Heavy metals	sub-city	Sample size	Mean rank	Chi-square	p
Fe	Akaki-Kality	56	45.68	4.155	0.042^∗
Fe	Gullele	45	57.62	4.155	0.042^∗
Zn	Akaki-Kality	56	55.75	3.402	0.065
Zn	Gullele	45	45.09	3.402	0.065
Cu	Akaki-Kality	56	55.66	4.873	0.027^∗
Cu	Gullele	45	45.20	4.873	0.027^∗
Mn	Akaki-Kality	56	46.80	2.867	0.090
Mn	Gullele	45	56.22	2.867	0.090
Pb	Akaki-Kality	56	51.86	0.114	0.736
Pb	Gullele	45	49.93	0.114	0.736
As	Akaki-Kality	56	56.73	8.638	0.003^∗
As	Gullele	45	43.87	8.638	0.003^∗

^∗

Indicates significant difference in heavy metal concentrations between Sub-Cities