Answer: Since you didn't include the picture, I can give you the description so you know how to pick the correct answer.
The third quartile of a data is always shown in a box plot. In the middle of your graph should be a box. The third quartile is the value that goes with the far right edge of the box.
Answer: 6 gallons
Step-by-step explanation:
4 gallons of water for 30 plants
turn into ratio
4:30
simplify
2:15
multiply both sides by 3 to get 45 plants
6:45
6 gallons for 45 plants