AP Statistics Unit 2: Exploring Two-Variable Data

Unit 2 covers two-variable data: scatterplots, correlation, least-squares regression and residuals. Residual plots are the heart of the unit — they are what tells you whether a linear model was appropriate at all.

Practise this unit freeAll Statistics units
295 questions10 CED topics100% with a figure
How this unit behaves

What 295 questions on it look like

It spans 10 CED topics, which is wide enough that "I've studied this unit" is not a meaningful statement. Track your accuracy by topic, not by unit.

100% of the questions come with a figure — a graph, diagram or data display. Reading the figure correctly is most of the work before any content knowledge applies.

Residuals92
Correlation and Linear Regression89
Representing Two Categorical Variables89
Linear Regression Models6
Least Squares Regression5
Correlation5
Analyzing Departures from Linearity4
Statistics for Two Categorical Variables2

Questions per CED topic, top 8 of 10.

From the bank

Three real exploring two-variable data questions

Drawn from the practice pool, not from the mock papers.

Representing Two Categorical Variables · Using Probability and Simulation · with figure

The data display records record values on a common scale. Which panel shows that Category Gamma is the largest segment for Group Z?

  1. APanel A
  2. BPanel B
  3. CPanel Ccorrect
  4. DPanel D
  5. EPanel E
Why C is correct

Panel C shows that Category Gamma is the largest segment for Group Z.

This is a strictblind AP Statistics figure item. The stem withholds the data needed to choose an answer, and the answer must be determined from the segmented_bar rendered from render_spec. Conditional proportions must be compared from the displayed panel. The answer key is recomputed from the structured answer_rule.

Common mistakes. A common error is choosing a familiar-sounding statistics statement without checking the visual evidence in the figure.

Residuals · Using Probability and Simulation · with figure

The visual summary is based on trial summaries. Which panel shows a wave-like residual pattern?

  1. APanel A
  2. BPanel Bcorrect
  3. CPanel C
  4. DPanel D
  5. EPanel E
Why B is correct

Panel B shows a wave-like residual pattern.

This is a strictblind AP Statistics figure item. The stem withholds the data needed to choose an answer, and the answer must be determined from the residual_plot rendered from render_spec. The matching residual pattern must be identified from the displayed panel, not from the option text. The answer key is recomputed from the structured answer_rule.

Common mistakes. A common error is choosing a familiar-sounding statistics statement without checking the visual evidence in the figure.

Correlation and Linear Regression · Data Analysis · with figure

The data display records standardized readings on a common scale. Which marked point is farthest to the right?

  1. APoint A
  2. BPoint B
  3. CPoint Ccorrect
  4. DPoint D
  5. EPoint E
Why C is correct

Point C has the largest explanatory-variable value.

This is a strictblind AP Statistics figure item. The stem withholds the data needed to choose an answer, and the answer must be determined from the scatterplot rendered from render_spec. The correct point label must be read from the displayed scatterplot. The answer key is recomputed from the structured answer_rule.

Common mistakes. A common error is choosing a familiar-sounding statistics statement without checking the visual evidence in the figure.

295 questions on this unit, free to start.

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FAQ

Exploring Two-Variable Data questions

What does a residual plot show?

Whether a linear model fits. Random scatter supports it; a pattern means the relationship is not linear.

Does correlation imply causation?

No, and the exam tests this directly. Only a randomised experiment supports a causal claim.
Last reviewed 2026-08-28. Unit and topic names follow the College Board course framework. Question counts describe the PrepScore practice bank, not the exam.
Topic by topic

Worked questions by topic

2 of this unit’s topics have enough practice questions for a page of their own.

Correlation and Linear Regression94 questionsResiduals92 questions
Same course
Unit 1: Exploring One-Variable Data460 questionsUnit 3: Collecting Data190 questionsUnit 4: Probability, Random Variables, and Probability Distributions100 questionsUnit 5: Sampling Distributions70 questionsUnit 6: Inference for Categorical Data: Proportions107 questionsUnit 7: Inference for Quantitative Data: Means63 questionsUnit 9: Inference for Quantitative Data: Slopes133 questions

Practise exploring two-variable data until the reasoning is automatic.

Real AP questions with a full explanation on every answer, and a mistake bank that only clears when you get it right.

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