Answer:
The slope is 2.5 and that means that 2.5 millimeters of rain falls every hour.
Explanation:
We can clearly see that the graph is moving in a positive direction, so we know our slope will be positive. Using the rise over run technique, we will have to rise 5 and move right 2 units in order to get from the first point to the second point. 5/2 = 2.5
So every hour, 2.5 mm of rain falls.