We study relationships among numerical variables using
A) correlation
B) covariance
C) scatterplot charts
D) all of these options
E) none of these options

Question

Quizplus · Accepted Answer

All of the options (correlation, covariance, scatterplot charts) are useful in studying relationships among numerical variables. 
- Correlation measures the strength and direction of the linear relationship between two variables. 
- Covariance measures the direction of the relationship between two variables, but its value is not standardized and thus cannot be used to directly compare the strength of relationships across different pairs of variables. 
- Scatterplot charts provide a visual representation of the relationship between two variables, allowing us to identify patterns such as linearity, curvature, and outliers.

We Study Relationships Among Numerical Variables Using