1. **State the problem:** We are given the number of point defects on the surface of 10 bus bodies and need to construct a c-chart, which is a control chart for count data (defects). 2. **List the data:** Body No.: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 Defects: 17, 11, 7, 11, 14, 6, 16, 10, 2, 6 3. **Calculate the average number of defects (center line $\bar{c}$):** $$\bar{c} = \frac{17 + 11 + 7 + 11 + 14 + 6 + 16 + 10 + 2 + 6}{10} = \frac{100}{10} = 10$$ 4. **Calculate control limits:** For a c-chart, control limits are given by: $$UCL = \bar{c} + 3\sqrt{\bar{c}}$$ $$LCL = \bar{c} - 3\sqrt{\bar{c}}$$ Since defects cannot be negative, if LCL is less than 0, set LCL = 0. Calculate: $$\sqrt{10} \approx 3.162$$ $$UCL = 10 + 3 \times 3.162 = 10 + 9.486 = 19.486$$ $$LCL = 10 - 9.486 = 0.514 \approx 0.514$$ Since LCL > 0, keep as is. 5. **Interpretation:** - Center line (CL) = 10 - Upper control limit (UCL) ≈ 19.49 - Lower control limit (LCL) ≈ 0.51 6. **Check if any points fall outside control limits:** All defect counts are between 2 and 17, so all points lie within control limits. 7. **Conclusion:** The process appears to be in control since all defect counts fall within the control limits. There is no evidence of special cause variation in the number of defects on the bus bodies.