Statistics & Probability
GradesGrade 8Statistics & ProbabilityScatter Plots & Association

Scatter Plots & Association

📊 Statistics & Probability
✦

Scatter Plots & Association

A scatter plot reveals the relationship between two numerical variables — look for direction, form, and strength.

A scatter plot displays bivariate data — pairs of values for two numerical variables, one on each axis. The pattern of points reveals whether and how the variables are associated, and whether any individual points are outliers.

Describing association in a scatter plot:

Positive association: as x increases, y tends to increase (points slope up-right)Negative association: as x increases, y tends to decrease (points slope down-right)No association: no clear pattern in the pointsLinear: points cluster along a straight lineNonlinear: points follow a curved patternOutlier: a point far from the main cluster
📚Study time vs. test scores
x-axis: hours studied per week (1, 2, 3, 4, 5)
y-axis: test scores (55, 62, 70, 78, 88)

As study time increases, test scores increase → positive association.
The relationship appears roughly linear.

Positive Association

Height vs. shoe sizeHours studied vs. test scoreAge vs. reading level

Negative Association

Speed vs. travel timeAltitude vs. temperaturePrice vs. number of buyers

Association does not imply causation — two variables can be correlated without one causing the other.

💡

Remember This!

An outlier in a scatter plot can strongly influence the line of best fit. Always check whether removing an outlier changes the pattern significantly.

✏️ Try It!

A scatter plot shows that as the number of absences increases, test scores decrease. What type of association does this show?

Practice with CalcVerse
📉Regression & Best Fit Line📊Histogram Builder
Take Quiz 📝 — 25 Questions