To find out how much Ethan earned per hour, you can divide his total earnings by the number of hours he worked.
Ethan's total earnings: $188.40
Total hours worked: 12 hours
Now, calculate the earnings per hour:
\[ \text{Earnings per hour} = \frac{\text{Total earnings}}{\text{Total hours worked}} = \frac{188.40}{12} \]
Calculating this gives:
\[ \text{Earnings per hour} = 15.70 \]
Therefore, Ethan earned $15.70 per hour.