1. **State the problem:** We need to find the fab's efficiency rate and utilization rate given the monthly design capacity, effective capacity, and actual production. 2. **Formulas:** - Efficiency rate = $\frac{\text{Actual Production}}{\text{Effective Capacity}} \times 100$% - Utilization rate = $\frac{\text{Actual Production}}{\text{Design Capacity}} \times 100$% 3. **Given values:** - Design Capacity = 76,790 wafers - Effective Capacity = 74,090 wafers - Actual Production = 72,050 wafers 4. **Calculate Efficiency Rate:** $$\text{Efficiency Rate} = \frac{72,050}{74,090} \times 100 = 0.9727 \times 100 = 97.27\%$$ 5. **Calculate Utilization Rate:** $$\text{Utilization Rate} = \frac{72,050}{76,790} \times 100 = 0.9381 \times 100 = 93.81\%$$ 6. **Final answers:** - Efficiency Rate = 97.27% - Utilization Rate = 93.81%