1. **Problem statement:** Convert the price of a phone case from yen to dollars, apply a tariff, and calculate the percentage profit. 2. **Given:** Exchange rate: $1 = 7.17$ yen Price per phone case: 28 yen Tariff: 15% Selling price in US market: 6.45 dollars 3. **Part (a): Convert price to dollars** Formula: $\text{Price in dollars} = \frac{\text{Price in yen}}{\text{Exchange rate}}$ Calculate: $$\text{Price in dollars} = \frac{28}{7.17}$$ Intermediate step with cancellation: $$\frac{\cancel{28}}{\cancel{7.17}} = 3.9047...$$ Rounded to nearest cent: $$3.90$$ 4. **Part (b): Apply 15% tariff** Formula: $\text{Total cost} = \text{Price in dollars} \times (1 + \text{tariff rate})$ Calculate: $$3.90 \times (1 + 0.15) = 3.90 \times 1.15 = 4.485$$ Rounded to nearest cent: $$4.49$$ 5. **Part (c): Calculate percentage profit** Formula: $\text{Profit percentage} = \frac{\text{Selling price} - \text{Cost price}}{\text{Cost price}} \times 100$ Calculate: $$\frac{6.45 - 4.49}{4.49} \times 100 = \frac{1.96}{4.49} \times 100 = 43.65\%$$ Rounded to nearest whole number: $$44\%$$ **Final answers:** (a) $3.90$ dollars (b) $4.49$ dollars (c) $44\%$ profit