1. Stating the problem: Calculate 8.5% of 620. 2. Formula: To find a percentage of a number, use the formula $$\text{Percentage value} = \frac{\text{percentage}}{100} \times \text{number}$$. 3. Calculation for 8.5% of 620: $$8.5\% = \frac{8.5}{100}$$ $$= 0.085$$ $$0.085 \times 620 = 52.7$$ 4. Stating the second problem: Calculate 2 1/2 % of 3450. 5. Convert mixed percentage to decimal: $$2 \frac{1}{2}\% = 2.5\% = \frac{2.5}{100} = 0.025$$ 6. Calculation for 2.5% of 3450: $$0.025 \times 3450 = 86.25$$ Final answers: - 8.5% of 620 = 52.7 - 2 1/2 % of 3450 = 86.25