Table 4 Statistical error parameters to measure the precision of the presented models in this research to approximate biodiesel surface tension.

Training set

AAPRE

1.88

0.98

APRE

− 0.08

− 0.16

RMSE

0.681554

0.429125

SD

0.000569

0.000228

R²

0.824

0.9266

Number of data points

63

63

Test set

AAPRE

1.90

0.95

APRE

0.99

0.30

RMSE

0.659574

0.4874

SD

0.000132

0.000274

R²

0.8484

0.9168

Number of data points

15

15

Total

AAPRE

1.89

0.97

APRE

0.13

 − 0.07

RMSE

0.677046

0.44093

SD

0.000479

0.000233

R²

0.831

0.9233

Number of data points

78

78