Answer:
try that it should help you with you question
Step-by-step explanation:
https://www.khanacademy.org/math/cc-2nd-grade-math/x3184e0ec:data/cc-2nd-bar-graphs/v/creating-bar-charts-1
3 more canisters explanation: 40/4=10, 28/4=7, 10-7=3 more canisters
Not exactly sure what values are represented here.