For a hypothetical gaseous reaction at 300 K : X (g) arrow Y (g) +...

For a hypothetical gaseous reaction at $300\text{ K}$:
$X\text{ (g)} \rightarrow Y\text{ (g)} + 2Z\text{ (g)}$
The standard internal energy change ($\Delta U^{\ominus}$) is $15.02\text{ kJ mol}^{-1}$ and the standard entropy change ($\Delta S^{\ominus}$) is $80\text{ J K}^{-1}\text{ mol}^{-1}$.
Determine the standard Gibbs free energy change ($\Delta G^{\ominus}$) and predict the spontaneity of the process at this temperature.
(Assume $R = 8.3\text{ J K}^{-1}\text{ mol}^{-1}$)