Metals	Cadmium	Manganese	Zinc	Aluminium	Copper	Lead
Difference	0.0168	0.0184	0.2407	0.0146	0.2703	0.0026
z (Observed value)	16.8815	11.0799	6.7616	10.5199	7.2186	2.3669
|z| (Critical value)	1.9600	1.9600	1.9600	1.9600	1.9600	1.9600
p-value (Two tailed)	< 0.0001	< 0.0001	< 0.0001	< 0.0001	< 0.0001	0.0179