6. Suppose that the diameters of different types of hairs are 1.9 × 10^–4 cm, 2.4 × 10^–5 cm, 1.2 × 10^–4 cm, and 1.8 × 10^–4 cm. What is the order of the hairs from least to greatest diameter? (1 point
1. 2.4 × 10^–5 cm
2. 1.2 × 10^–4 cm
3. 1.8 × 10^–4 cm
4. 1.9 × 10^–4 cm