Answer:
5 1/2 cubic yards
Explanation:
You want the volume of a 4 inch layer of topsoil for a 14 ft by 31 ft garden to the next higher 1/4 cubic yard.
Volume
We can find the volume in cubic yards by first converting all of the dimensions to yards:
4 in = 4/36 yd = 1/9 yd
14 ft = 14/3 yd
31 ft = 31/3 yd
The volume is the product of these dimensions:
V = LWH = (1/9 yd)(14/3 yd)(31/3 yd) = 434/81 yd³ = 5 29/81 yd³
That's about 5.36 yd³. The next higher 1/4-yd³ increment is 5.5, so you will need to order 5.5 cubic yards.