A certain substance $x$ has a normal freezing point of $4\mathrm{.}7C$ and a molal freezing point depression constant $K_f=3\mathrm{.}87C*kg*mo{l}^{-1}*A$ solution is prepared by

dissolving some urea $((N{H}_2{)}_{2}CO)$ in $750g$ of $x.$ This solution freezes at $-0\mathrm{.}9C.$ Calculate the mass of urea that was dissolved.

Round your answer to $2$ significant digits.