scatter() — Scatter plot

One dot per pair — shows how two things relate.

plot(x, y)

Key idea

• Scatter places one dot for each pair of x (left-right) and y (up-down) values. (e.g. (height 170, weight 65))
• It reveals whether two numeric variables move together — their relationship, or correlation.
• An upward cloud of dots suggests a positive relationship (both rise together). (e.g. more study hours, higher scores)
• Scattered dots with no pattern suggest little or no relationship.
• Outliers — unusual points far from the rest — stand out from the main group. (e.g. one point at (5, 95))

In plain words

Each dot is one thing measured two ways — does the cloud of dots tilt up, tilt down, or stay flat?

Where you'd use it

• Plot each student’s study hours against their exam score. If the cloud of dots tilts clearly upward — more hours, higher scores — a scatter reveals the relationship before you ever compute a correlation.
• Charting students’ height against weight usually shows dots drifting up to the right, telling you taller students tend to weigh more.
• A scatter of monthly ad spend versus sales that forms a rising band suggests spending more brings more sales, while a shapeless blob would mean little connection.

Frequently asked questions

What does a scatter plot show?

The relationship between two numeric variables — look for trend, spread and outliers.