Understanding Scatter Graphs in Year 10 Math

Scatter graphs are really useful tools in Year 10 math. They help students understand how two numbers are related to each other.

What Scatter Graphs Do:

1. Finding Relationships:

   • Positive Correlation: When one number goes up, the other usually goes up too. For example, taller people often weigh more.
   • Negative Correlation: When one number goes up, the other goes down. For example, the faster you go, the less time it takes to travel a certain distance.
   • No Correlation: There is no clear connection between the two numbers. For instance, your shoe size doesn't really say anything about how smart you are.

2. Checking How Strong the Relationship Is:

   • Strong Correlation: The points on the graph are very close to a straight line.
   • Weak Correlation: The points are spread out but might still show a pattern.

3. Using Numbers to Measure Relationships:

   • The correlation coefficient (called $r$) can help us see how strong the relationship is. It goes from $-1$ to $1$:
     • If $r$ is close to $1$: There is a strong positive relationship.
     • If $r$ is close to $-1$: There is a strong negative relationship.
     • If $r$ is close to $0$: There is little or no relationship.

By looking at scatter graphs, students can draw conclusions about different situations in the real world using numbers and data.