Answer:
- Divide the mass of sodium sulfate in pounds (3.99 lb) by the conversion factor (2.2046226 lb/kg): 3.99 lb / 2.2046226 lb/kg = 1.81 kg.
- Round it to the nearest hundredth to get the answer: 1.81 kg = 1.81 kg (no rounding needed, 'cause it's already precise to the nearest hundredth).
So, the mass of sodium sulfate in the container is approximately 1.81 kg.