Well if you are looking for the profit margin we need how much is was when she bought it, because it doesn't say, you can't say It's a increase or a decrease, so you could say this is a investment.
But considering you put this under mathematics I assume there is more to this question you forgot to post.
Answer:
The area of a label is 
Step-by-step explanation:
we know that
The lateral area of a cylinder (label of the can) is equal to

we have that
A can is 4 inches wide
so
The diameter of the can is 4 inches
----> the radius is half the diameter
----> height of the label
substitute in the formula

Choose your points, go up from the y intercept to a chosen x point. Then go over the the x point. Up and over is the formula I use.
Answer:
all work is shown / pictured