To find the unit rate (cost per ounce), divide the total cost by the total ounces.
Given:
- Total cost = $5.99
- Total ounces = 12.4
Now, calculate the unit rate:
\[ \text{Unit rate} = \frac{\text{Total cost}}{\text{Total ounces}} = \frac{5.99}{12.4} \approx 0.4823 \]
Rounding this to the nearest cent:
\[ 0.4823 \approx 0.48 \]
Thus, the unit rate is:
\[ \boxed{0.48} \] per ounce.