A teaching assistant performs an experiment using an aluminum container, with a mass of $0\mathrm{.}150$ kg$,$ that contains $0\mathrm{.}285$ kg of water, all initially at $30\mathrm{^.}$⁰ C$.$ The teaching assistant then adds a sample of an unknown substance to the water. The sample has a mass of $1\mathrm{.}5$ kg and an initial temperature of $98\mathrm{.}0$^o C$.$ After waiting until the entire system reaches thermal equilibrium, the teaching assistant measures a final temperature of $32\mathrm{.}0$ ^o C$.$ What is the specific heat $($in J$/($kg$$ ^o C$))$ of the unknown substance? You may assume the thermal energy transferred to the environment during the experiment is negligible.