SAT Math · Study & Practice

Two-Variable Data

Two-variable data looks at how one quantity relates to another, shown on a scatterplot and summarised by a line of best fit. This chapter covers scatterplots, correlation, positive and negative correlation, and regression concepts. Read each topic, work the problems with the hint ladder, then take the 8-question topic test.

Topics

1 Scatterplots 4 worked · 5 practice · 8-Q test Start → 2 Correlation 4 worked · 5 practice · 8-Q test Start → 3 Positive Correlation 4 worked · 5 practice · 8-Q test Start → 4 Negative Correlation 4 worked · 5 practice · 8-Q test Start → 5 Regression Concepts 4 worked · 5 practice · 8-Q test Start →

Chapter test

📝 Two-Variable Data — Chapter Test

25 fresh questions · timed · full solutions

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Formula Reference Sheet

This chapter

Describing data

Positive association	y rises as x rises
Negative association	y falls as x rises
Strength	how closely points hug the line

Line of best fit

Form	y = mx + b
Prediction	substitute an x-value to estimate y
Residual	actual y − predicted y

Digital SAT reference

Area & Circumference

Circle area	A = πr²
Circle circumference	C = 2πr
Rectangle	A = ℓw
Triangle	A = ½ b h

Volume

Rectangular box	V = ℓwh
Cylinder	V = πr²h
Sphere	V = 4⁄3 πr³
Cone	V = 1⁄3 πr²h
Pyramid	V = 1⁄3 ℓwh

Right triangles

Pythagorean theorem	a² + b² = c²
30°–60°–90°	sides x : x√3 : 2x
45°–45°–90°	sides s : s : s√2

Constants

Degrees in a circle	360°
Radians in a circle	2π
Angles of a triangle	sum = 180°