Relationships between two variables
Examine relationships in scatter plots and distinguish correlation from causation.
Meaning
A scatter plot represents pairs of numerical values as points. Correlation is a tendency to vary together; it does not mean that one variable causes the other.
Example
Ice cream sales and visits to swimming areas may both increase in hot weather, but this does not show that ice cream sales cause swimming visits. Temperature may be a shared factor. A correlation coefficient mainly summarizes a linear relationship. A value near zero does not rule out a curved relationship.
Practice for this concept
Scope and references
Topics
Scatter plots, correlation, correlation versus causation
Learning goal
Examine relationships in scatter plots and distinguish correlation from causation.
Helpful background
Review coordinates, the meanings of both variables, and collection conditions.
Relationships between two variables
These choice exercises calculate or judge specified finite data, trials, or assumptions. They do not establish data collection, written inference, model validation, or mastery of the whole statistics area.