1. **Problem statement:** At a school, 60% of the students are girls. 45% of the girls and 15% of the boys are overweight. Find the percentage of overweight students in the school. 2. **Formula and explanation:** To find the overall percentage of overweight students, use the weighted average formula: $$\text{Total overweight %} = (\text{Percentage of girls} \times \text{Overweight % of girls}) + (\text{Percentage of boys} \times \text{Overweight % of boys})$$ 3. **Calculate the percentage of boys:** Since 60% are girls, the remaining 40% are boys. 4. **Substitute the values:** $$= 0.60 \times 0.45 + 0.40 \times 0.15$$ 5. **Calculate each term:** $$= 0.27 + 0.06$$ 6. **Add the results:** $$= 0.33$$ 7. **Convert to percentage:** $$0.33 \times 100 = 33\%$$ **Final answer:** The percentage of overweight students in the school is 33%.