Chapter 10 - Statistics - 10.2 Bar Graphs and Line Graphs - 10.2 Exercises - Page 720: 20

$$200 \ gallons $$

We are asked about regular gasoline, so we only look at the purple bars. In 2013, we see that 400 gallons were sold. In 2017, we see that 600 gallons were sold. Thus, the increase is: $$ = 600 -400 \\ = 200 \ gallons $$