1. **State the problem:** Ethan earned 188.40 for 12 hours of work. We need to find how much he earned per hour. 2. **Formula:** The unit rate (earnings per hour) is calculated by dividing the total earnings by the total hours worked. $$\text{Unit rate} = \frac{\text{Total earnings}}{\text{Total hours}}$$ 3. **Substitute the values:** $$\text{Unit rate} = \frac{188.40}{12}$$ 4. **Simplify the fraction:** $$\frac{\cancel{188.40}}{\cancel{12}} = 15.7$$ 5. **Interpretation:** Ethan earned 15.7 per hour. **Final answer:** Ethan earned $15.7 each hour.