A tank contains $5 \mathrm{~kg}$ of air at an absolute pressure of $280 \mathrm{kPa}$ and a temperature of $27^{\circ} \mathrm{C}$. If $1.5 \mathrm{~kg}$ of air is added to the tank and the temperature rises to $37^{\circ} \mathrm{C}$, determine the pressure in the tank.