Iam confused my teacher on the first problem but the rest didn't make sense any idea's?

2. The three points you need to mark on this graph are (1,2) (2,3) and (4,5); you then draw a line through all of these points and determine whether the inches of rainfall is proportionate to the number of hours. 

You mark those 3 points because at 1 hour, 2 inches of rain has fallen; at 2 hours, 3 inches of rain has fallen; and at 4 hours, 5 inches of rain has fallen