Parametera Estimatesb Asymptotic S.E. 95% Asymptotic Confidence Intervalsc
α 389.6 83.72 219.3 - 559.9
β 5.13 0.82 3.47 - 6.79
c 0.99 0.40 0.178 - 1.81
a Y=αe – β x + c; where α is the intercept, β represents the exponential rate of decay of CFU, and c is the lower asymptote.
b Significance of the parameter estimates determines adequacy of fit of the model.
c 95% asymptotic confidence interval on model parameters do not encompass 0, indicating significance of parameter estimates at P<0.05.
Table 3: Estimated parameter, standard errors (S.E.), and associated asymptotic confidence intervals for the non-linear regression model of S. aureus colony forming units (CFU) at 24 h, treated with different concentrations of PGF.