calculated slopes lie in the range $1.0-1.2$ for separations from 40 to 200 pc. In the outer range of $S$ (100-500 pc), the slopes $\alpha\approx0.5$ for pair samples in NGC 628 and NGC 6946. This slope turned out to be larger in NGC 3184 ($\alpha=0.91$), however, it is calculated with poor accuracy due to insufficient statistics. The mean slope at 40 pc $<S<$ 500 pc is a little less than 1: $\alpha=0.85\pm0.10$ for SC-H[ii]{}R pairs in all three galaxies (Table \[table:coeff\]). Coefficients $\beta$ differ from galaxy to galaxy. As we talked above, they are very sensitive to observational errors and model uncertainties.

The dependence in the peculiar galaxy NGC 5585 shows the approximately constant slope $1.4-1.6$ at all separation ranges. Unfortunately, the coefficient $\alpha$ is determined with a very large error.

SC-H[ii]{}R pairs in the asymmetric galaxy NGC 3726 show a rather chaotic distribution on the diagram $\log t - \log S$. This scatter can be caused by various parameters of the medium in the asymmetric disc of the galaxy. Nevertheless, the mean slope at a general range of $S$ is equal to 1.22, that is close to the mean slope in NGC 5585.

Plots in Fig. \[figure:age\_sep\] show that 