Answer:
Hope i helped but i am not sure chief if that is what you needed
Step-by-step explanation:
you said in the comment we need to find the gallons so if we have the cost 10$ per 2 gallons then 20$ per 4 gallons. Then technicly 1 gallon will be 0 $
But if we need to find the value of the red dots it's starting from the top
40$ for the value of 8
30$ for the value for 6
20 $ for the value of 4
10$ for the value of 2
You can conclude that the cost bar increases by 2 each time
