Answer
$$4.03 \space oz \space used$$
Work Step by Step
1. Identify the equalities and conversion factors that we will use to solve this problem:
$$8\% \space used = 100 \% \space total$$ $$1 \space lb = 16 \space oz*$$ $$1 \space kg = 2.20 \space lb*$$ * Check Table 2.7 (Page 38)
2. Solve the problem using multiple conversion factors:
$$1.43 \space kg \space total \times \frac{8\% used}{100\% total} \times \frac{2.20 \space lb}{1 \space kg} \times \frac{16 \space oz}{1 \space lb} = 4.02688 \space oz \space used$$
- Rounding off to 3 significant figures:
$$4.03 \space oz \space used$$
