Table 4 Regression equation, correlation coefficient, and sum of the relative errors for each weighted and unweighted factor

1

Unweighted

y = 96732x − 16734

0.9997

65.45

2

1/√x

y = 98963x + 32786

0.9994

51.32

3

1/x

y = 96289x − 18764

0.9993

44.57

4

1/x²

y = 99726x + 9978

0.9996

34.65

5

1/√y

y = 98786x + 16783

0.9993

57.45

6

1/y

y = 95638x − 18976

0.9998

56.32

7

1/y²

y = 97863x − 26134

0.9995

39.67