What is a Scatter Plot?
A scatter plot (also called a scatter graph or correlation chart) uses Cartesian coordinates to display values for typically two variables for a set of data. The data is displayed as a collection of points, each determining the position on the horizontal axis (X) and vertical axis (Y).
When should you use a Scatter Plot?
Scatter plots are primarily used to discover and model relationships between numerical variables. Use a scatter plot when:
- You suspect there is a relationship or correlation between two numeric variables.
- You want to determine if the correlation is **positive, negative, linear, or non-linear**.
- You need to identify **outliers** (data points that deviate significantly from the general trend).
Understanding Scatter Plot Correlations
- Positive Correlation: As X increases, Y increases. The points form an upward trajectory.
- Negative Correlation: As X increases, Y decreases. The points form a downward trajectory.
- No Correlation: The points are scattered randomly, indicating no statistical relationship between the variables.