(a) Given that 40 ounces of Lazy Lawn fertilizer cover 1,250 square feet of lawn, let be "x" the number of ounces that would be required to cover a 9,000 square foot law.
You can set up the following proportion:

Now you need to solve for "x", in order to find its value:


(b) You know that Lazy Lawn costs $1.11 for a 36-ounce bag.
Let be "c" the total cost (in dollars) to fertilize the 9,000 square-foot lawn.
Knowing that 288 ounces are required to cover that lawn, you can set up this proportion:

Solving for "c", you get:


Hence, the answers are:
(a)

(b)
