The percent concentration of the Barium nitrate : 11.33%
Further explanation
The concentration of a substance can be expressed in several quantities such as moles, percent (%) weight/volume,), molarity, molality, parts per million (ppm) or mole fraction. The concentration shows the amount of solute in a unit of the amount of solvent.

mass solute=mass Barium nitrate(Ba(NO₃)₂)=46 g
mass solvent=mass water=360 g
mass solution=mass solute+mass solvent=46+360=406 g
