$11\mathrm{.}00g$ of Compound $x$ with molecular formula $C_4{H}_8$ are burned in a constant$-$pressure calorimeter containing $30\mathrm{.}00kg$ of water at $25C.$ The temperature of the water is observed to rise by $3\mathrm{.}943C.($You may assume all the heat released by the reaction is absorbed by the water, and none by the calorimeter itself.$)$ Calculate the standard heat of formation of Compound $x$ at $25C.$

Be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits.