A positive correlation in a scatter graph means that when one thing goes up, another thing usually goes up too. But figuring this out can be tricky:

• Misleading Relationships: Just because two things change together doesn't mean one causes the other to change.
• Outliers: Sometimes, there are data points that are very different from the rest. These can give a wrong idea about how things are related.

To make sense of these challenges, you should:

1. Look at the background of the data.
2. Think about using statistical tools, like the correlation coefficient ($r$), to measure how closely the two things are related.