Temperature of a reaction with an activation energy value of $15 \mathrm{kcal} \mathrm{mol}^{-1}$ is increased from $300 \mathrm{~K}$ to $310 \mathrm{~K}$. If the value of the ideal gas constant $(\mathrm{R})$ is $1.9872 \mathrm{cal} . \mathrm{mol}^{-1} \cdot \mathrm{K}^{-1}$, the ratio of the reaction rate constants $\left(k_{310} / k_{300}\right)$(rounded off to two decimal places) is _____________.