How are the changes in the frequencies of heat waves in the six cities similar? They are similar because they all get bigger. There are no negative numbers in the charts, so there have been more than before.
How are they different? They are different because they describe heat waves in different states. The farther west you go, the more heat waves there are.
What do the data indicate about the likelihood of future heat waves?
It shows that states farther west get more, therefore the western states should be more worried about heat waves.
How would you advise these cities to prepare for this future weather?
Use air conditioners, fans, and stay hydrated.