Chemical Thermodynamics: JEE Main 2025 Chemistry question

Consider the following cases of standard enthalpy of reaction ($\Delta H^\circ_r$ in kJ mol$^{-1}$) $\mathrm{C_2H_6(g) + \frac{7}{2}O_2(g) \to 2CO_2(g) + 3H_2O(l)}$ $\Delta H^\circ_1 = -1550$ $\mathrm{C(graphite) + O_2(g) \to CO_2(g)}$ $\Delta H^\circ_2 = -393.5$ $\mathrm{H_2(g) + \frac{1}{2}O_2(g) \to H_2O(l)}$ $\Delta H^\circ_3 = -286$ The magnitude of $\Delta H^\circ_{f\, \mathrm{C_2H_6(g)}}$ is ______ kJ mol$^{-1}$ (Nearest integer).