The estimated regression coefficients of Eq. (2) and ANOVA for yield of biodiesel production in SCM are shown in Tables 5 and 6, respectively.
Since the p-values of all the linear, quadratic and two of the interaction coefficients are less than 0.05, these coefficients
have significant influence on biodiesel yield in SCM transesterification (confidence level is 95%).
The p-value of the lack-of-fit analysis is 0.409 which is greater than 0.05.