Answer:
12°C
Step-by-step explanation:
According to the graph, the x axis are the months while the y axis denotes the varying temperature of both cities every month.
Considering July, the temperature of San Francisco during this month is approximately 14°C. This is gotten by locating the point on the line of San Francisco during July and tracing it perpendicularly to the temperature axis to know its equivalent temperature during that month.
Similarly, the temperature of St. Louis in July is high compare to San Francisco and it is approximately 26°C.
Therefore, the difference in average temperature is 26°C - 14°C = 12°C