Final answer:
The volume of the water trough when full is found by multiplying the width, length, and height dimensions, resulting in a volume of 70 cubic feet.
Step-by-step explanation:
To find the volume of the water trough when it is full, we use the formula for the volume of a rectangular prism, which is the product of its length, width, and height. Given the dimensions of the trough in feet are 4 ft (width), 7 ft (length), and 2.5 ft (height), the volume is calculated as:
Volume = width × length × height
Volume = 4 ft × 7 ft × 2.5 ft
Volume = 70 cubic feet
Therefore, the volume of water the trough can hold when full is 70 cubic feet.