z_model vs. z_obs, comparing two prior assumptions on the $A_{\tau }\stackrel{\sim }{F}G$ ranges using the 30 FRB samples and our method. The blue points with error bars assume $A_{\tau }\stackrel{\sim }{F}G$ =[0.001, 10] ${({\mathrm{pc}}^2\mathrm{km})}^{-\frac{1}{3}}$. The orange points with error bars assume $A_{\tau }\stackrel{\sim }{F}G$ =[0.5, 2] ${({\mathrm{pc}}^2\mathrm{km})}^{-\frac{1}{3}}$. To demonstrate how the result depends on the prior assumption on the $A_{\tau }\stackrel{\sim }{F}G$ range, the identical value of f_IGM × H₀ = 63.2 km s⁻¹ Mpc⁻¹ is adopted for both cases.