Groupthink, hope this helped
Answer: San Francisco has the highest cost of living of the three
Explanation:
As shown by the graph, San Francisco costs the most. So, this is the only obvious assumption you can make by the graph.
The other three are either incorrect or simply predicted based on the facts given. However, the question is asking what best explains the graph, rather than what can be predicted. So, saying San Francisco costs the much, that would explain what is shown on the graph.
To find a slope in algebra (always) use
y=mx+b
mx is slope
b is y-intercept
line them up with an equation and graph it in the end
