Answer:
6 pounds of fertilizer is required to cover an area of 180 square feet.
Step-by-step explanation:
We are given the following in the question:
We have to use 4 pounds of fertilizer for 120 square feet of soil.
We find the equivalent ratio of area of soil and amount of fertilizer used.
Ratio =

This means that 30 square feet of soil requires 1 pound of fertilizer.
Area of the garden = 180 square feet
Let x be the amount of fertilizer required.
Thus, we can write:

Thus, 6 pounds of fertilizer is required to cover an area of 180 square feet.