1. **State the problem:** We have a pie chart representing the number of siblings of 60 people. The chart is divided into four slices with central angles 36°, 108°, 108°, and 108°, corresponding to 1, 0, 2, and 3 siblings respectively. 2. **Formula and concept:** The number of people represented by each slice is proportional to the central angle of that slice. The total angle in a circle is 360°. 3. **Calculate the number of people for the slice with 3 siblings:** The slice for 3 siblings has a central angle of 108°. Number of people with 3 siblings = Total people × (Angle for 3 siblings / Total angle) $$\text{People with 3 siblings} = 60 \times \frac{108}{360}$$ 4. **Simplify the fraction:** $$\frac{108}{360} = \frac{\cancel{108}}{\cancel{360}} = \frac{3}{10}$$ 5. **Calculate the number:** $$60 \times \frac{3}{10} = 6 \times 3 = 18$$ 6. **Answer:** There are **18 people** who have 3 siblings.