Model #

Independent variable(s)

Predictive Model

R² value

9.

As

$\widehat{Cd}$ = 0.84 As − 61.08

90.0%

10.

Co

$\widehat{Cd}$ = 0.95 Co − 26.45

96.9%

11.

Cr

$\widehat{Cd}$ = 0.89 Cr − 7.93

98.5%

12.

Fe

$\widehat{Cd}$ = 0.02 Fe − 2.14

17.3%

13.

Pb

$\widehat{Cd}$ = 0.44 Pb − 41.56

34.5%

14.

Sb

$\widehat{Cd}$ = 0.52 Sb − 94.89

49.3%

15.

Tl

$\widehat{Cd}$ = 0.94 Tl − 16.88

92.4%

16.

As, Co, Cr, Fe, Pb, & Tl

$\widehat{Cd}$ = 0.06 AS + 0.38 Co + 0.50 Cr − 0.01 Fe − 0.02 Pb + 0.07 Tl − 4.77

99.6%