where Xp is the predicted kinematic viscosity,and Xo is theobserved or measured kinematic viscosity.
The results from the ANOVA (see Table 1) show that the {3,3} simplex lattice augmented with interior points can be applied to screen for and optimize the kinematic viscosity of Jatropha biodiesohol because of the good fit to the full cubic model with an excellent MAPE. In addition, MAPE and the scatter plot between the prediction and observation (Fig. 3) show low residuals because of the low MAPE; this result is defined as an excellent equation to