Step-by-step explanation:
just look at the graphic : what value do we have on the cost side, when we have 1 pounds on the amount side ?
all the answer options specify a price per pound. that is why we only need to focus on the price for one pound.
we see in the graphic, that for 1 pound the price is $4.
just to make sure, we can also work with the directly specified point (0.5, 2), which means that 0.5 pounds cost $2.
and the function is clearly a straight line.
so, every point on the function has the same y/x ratio (slope).
therefore,
2/0.5 = 4
now, what point with x=1 has the same ratio ?
y/1 = 4
y = $4
perfect, the results are identical. so, $4 per pound is the correct answer.
