Let r be the radius of convergence of the power series \(\frac{1}{3}+\frac{x}{5}+\frac{x^2}{3^2}+\frac{x^3}{5^2}+\frac{x^4}{3^3}+\frac{x^5}{5^3}+\frac{x^6}{3^4}+\frac{x^7}{5^4}+...\) Then the value of r2 is equal to _________. (Rounded off to two decimal places)