1. **State the problem:** A shopkeeper buys 48 radios for a total cost of 7200. We need to find the selling price per radio to make a 15% profit on the total cost. 2. **Calculate the cost price per radio:** $$\text{Cost price per radio} = \frac{7200}{48} = 150$$ 3. **Calculate the selling price per radio for 15% profit:** Profit is 15% of cost price, so $$\text{Profit per radio} = 0.15 \times 150 = 22.5$$ Selling price per radio is cost price plus profit: $$\text{Selling price} = 150 + 22.5 = 172.5$$ 4. **Conclusion:** The shopkeeper must sell each radio at 172.5 to make a 15% profit. **Final answer:** 172.5