On checking for the statistical significance of correlations between six physical properties of 131 constitutional isomers of alkanes with 6-10 carbon atoms and new topological indices based on the molecular path code analyzed previously in [A.T. Balaban, A. Beteringhe, T. Constantinescu, P. A. Filip, O. Ivanciuc, J. Chem. Inf. Model. 47 (2007) 716.], it was found that only the correlations with the density at 25 degrees C, the Gibbs free energy of formation in gaseous state, and the refractive index at 25 degrees C had valid high coefficients of determination, whereas the variance of the molar heat capacity and of the normal boiling point was due to clustering according to the number of carbon atoms. Correlations with the vaporization enthalpy had an intermediate position. (C) 2008 Elsevier B.V. All rights reserved.