Since the concentration was specified in PPM by volume, but both the fuel and the product are normally measured in KG (and have different densities), there were actually 4 calculations required:
1. Convert the 6200 KG of fuel to 7678 L.
2. Convert 100 PPM to .0001.
3. Multiply 7678 L of fuel by 0001 to get .7278 L of product.
4. Convert .7678 L of product to .799 KG.
And that's after looking up the specific gravities of both the fuel and the product.
If the procedure had said that 1 KG of product treated 7760 KG of fuel, the calculation would have looked like this:
1. 6200 KG divided by 7760 equals 0.799 KG.