Statistic feature

Cu

As

Pb

Hg

Cd

Range

5.03 - 66.26

2.42 - 13.52

7.85 - 45.17

0.016 - 0.06

0.047 - 0.186

Mean

18.90

6.70

19.93

0.04

0.09

Median

13.69

6.50

18.88

0.04

0.07

Root-mean-square deviation

13.76

2.15

9.35

0.01

0.04

Coefficientof variation

0.73

0.32

0.47

0.32

0.48