A chemist prepares a solution of silver perchlorate $(AgCl{O}_4)$ by weighing out $143\mathrm{.}5$ g of silver perchilorate into a $400.$ mL volumetric flask and filling the flak to the mark with water.

Calculate the concentration in $\frac{g}{d}L$ of the chemist's silver perchiorate salution. Be sure your answer has the correct number of significant digits.