The term you’re looking for is scatterplots.

Quick Scoop: What “are used when we want to visually examine the

relationship between two quantitative variables”?

Direct answer

Scatterplots are used when we want to visually examine the relationship between two quantitative variables.

They place one quantitative variable on the x‑axis and the other on the y‑axis, with each point representing one observation.

What a scatterplot shows

  • Direction of the relationship (positive, negative, or no clear trend).
  • Form (roughly linear, curved, or more complex).
  • Strength (how tightly the points cluster around an imagined line or curve).
  • Outliers (points that stand far away from the rest of the data).

A classic example is plotting height vs. weight for many people; each dot is one person, and the overall cloud of points tells you how the two variables move together.

Why scatterplots (and not other graphs)?

  • Bar charts are better for categorical comparisons, not for two quantitative variables.
  • Pie charts are for parts of a whole , not relationships.
  • Line graphs emphasize changes over an ordered scale (like time), whereas scatterplots are the default choice for general two‑variable quantitative relationships.

Because each dot encodes a pair of numbers, scatterplots are the most straightforward way to see association before computing statistics like correlation or regression.

A tiny story to lock it in

Imagine a teacher who records every student’s study hours and exam score for the latest test.
They put study hours on the horizontal axis and exam score on the vertical axis, then mark one point per student.
Very quickly, they notice that the dots climb upward from left to right: students who studied more tended to score higher.
What they just drew is a scatterplot, and it visually answers the question, “How are these two quantitative variables related?”

TL;DR:
When you see the phrase “are used when we want to visually examine the relationship between two quantitative variables” , the answer is: scatterplots.

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