Study the line chart below. What do you see?
This line chart is the same as you saw above, but the axes have been changed. In this plot, the differences in number of customers at the different times looks smaller. With small changes, information can be displayed very differently (manipulated) to present the picture you want. With statistics, it is often the case that if the publisher benefits from the differences in number of customers being small, they will press the second axis together. While if the publisher wants to make it clear that the discrepancy is large, they pull the second axis so that it becomes longer. Such manipulation is not good, but is unfortunately very widespread. So stay alert!
It is your responsibility to notice if information is being manipulated. It is therefore important that you look closely at how the information is presented, so you are not fooled! It is your responsibility to check sources and analyze charts when reading them. In order to fully understand the information you are given, you must have good math skills. Percentage calculation and basic arithmetic take you quite far.