Express the concentration of 6.2 micrograms per millilitre in kilograms per cubic metre

struggling with the conversion of this, any help would be greatly appreciated.

Multiply both by 1000 and we get 6.2 micrograms per ml. equals 6.2 milligrams per liter
Multiply them both by 1000 again and we get 6.2 grams per kiloliter.
1 liter equals 1 cubic decimeter, so 1 cu.meter equals 1 kiloliter.
So we have 6.2 grams per cu. meter which equals 0.0062 kg. per cu. meter
Hope this explanation helps show how I did it.