Explanation
To compute for the volume of the trough, use the formula:
\(\text { Volume }=\mathrm{L} \times \mathrm{W} \times \mathrm{H}=8 \mathrm{ft} \times 4 \mathrm{ft} \times 3 \mathrm{ft}=8 \times 4 \times 3=96 \text { cubic feet }\)
The information about 2.8 inches rise in slop is unnecessary.