What is the primary purpose of a scatter diagram?

To look for a relationship between two numerical variables.

Describe a situation where a scatter diagram would be a useful tool.

A scatter diagram would be useful to determine if there is a relationship between the amount of time students study and their exam scores.

When two variables are correlated, the points on the scatter diagram will fall along a line or curve, indicating a relationship between them.

Even if a scatter diagram shows a strong relationship, do not assume that one variable caused the other. Both may be influenced by a third variable.

There is no apparent connection between the two variables being plotted.

I can create and interpret scatter plots to investigate patterns of association between two variables.

1
A scatter diagram, also known as a scatter plot, X-Y graph, or correlation chart, is used to graph pairs of numerical data to identify potential relationships between them.
2
When using a scatter diagram, if the variables are correlated, the points will generally fall along a line or curve, and the stronger the correlation, the tighter the points will hug the line.
3
In Excel, to create a scatter diagram, you must first select the data, then go to the Insert tab, click on the Charts group, and select Scatter to choose the desired scatter chart type.