What is the concentration of SO42- in mg/L (ppm) for a solution that is 0.00457 M of K2SO4

What is the concentration of SO42- in mg/L (ppm) for a solution that is 0.00457 M of K2SO4?

1 mole of K2SO4=1 mole of SO4^2-

0.00457 moles of SO4^2-/L*(96.06 g/mol)=4.390 x 10^-1 g of SO4^2-/L

4.390 x 10^-1 g of SO4^2-*(10^3mg/1g)=4.390 x 10^-2 mg of SO4^2-/L

4.39 x 10^2 ppm or 439ppm SO4^2-

***Answer must contain 3 significant figures.