The way I interpreted from this graph is when the donations started their class got excited for donations and brought lot’s of money in September. Then they lost interest and the class mates started not to bring that much money near the end september and still lost interest in early October for the three day’s .So then the principal said who ever raises the most money will get a free movie to watch, then their class got so excited again and started raising lot’s of money for the free movie in October ( 2 day’s) . Then they went back down again, Then the teacher maybe told them how important It was to raise the money,then they probably got convinced so started to raise more money still in October .Guess what they won the free movie and so did our class.