I really like this question. It's subtle and interesting.
So here's a solution ....
We know the revenues in in E, K, C, and F from their horizontal position. Just in terms of gross revenue, it appears the order, from least to greatest, would be E, F, C, and K ---- that's just the order of the centers of the circles from left to right.
The tricky and interesting thing about this question --- we don't want total
revenue from each store, but rather, "average revenue per resident." This is a fraction:
average revenue per resident = (total revenue of that store)/(number of residents in that city)
We make a fraction as big as possible by (a) making the numerator as large as possible, and (b) making the denominator as small as possible. The number of residents (i.e. the denominator) is shown by the size
of the circles. E clearly has the biggest size, the biggest denominator, and it has the smallest numerator, so E would have the smallest average revenue. Circles F & C & K all appear about the same size --- so essentially, those denominators will all be the same, and the only thing that makes a difference in the size of those fractions would be the numerator. K has the biggest numerator, so it has the biggest value of the fraction ---- i.e. the biggest average revenue per resident.
Please let me know if anyone reading this has any further questions.
Magoosh Test Prep