Explore variability, design a fair investigation, and explain what a statistical result actually says.
Read 10 original sample questions with worked explanations before opening the practice studio. These examples introduce selected topics from this AP Statistics foundation path.
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What this practice covers
2026–27 foundation pilot; editorial topic-level mapping, not official alignment certification
Original four-option conceptual and numerical practice plus numeric learning exercises. Not a replica of the fully digital AP free-response exam.
10 public examples400 question variants in the studio96 task families
Review status: Independent educator review and learner calibration are pending. Use these selected foundation examples alongside the coverage map and current official references.
Four independently sampled participants have before scores [10, 20, 30, 40] and corresponding after scores [8, 22, 32, 42]. Assume the population of after-minus-before differences is approximately normal. For a one-sample t test of population mean change 0, what is the t statistic?
1/2
-1
2
1
Answer: 1
Form each participant difference, then compute its sample mean and sample SD before standardizing the mean change.
Differences are [-2, 2, 2, 2]; their mean is 1. Squared deviations sum to 12, so sample variance=12/3=4 and SD=2. SE=2/√4=1, giving t=(1−0)/1=1.
Why an alternative fails: Divide the mean change by the sample SD of differences, omitting the square-root-of-n adjustment.
Compare the other answer choices
2
Divide the difference SD by n rather than square root of n, making the standard error too small.
1/2
Divide the mean change by the sample SD of differences, omitting the square-root-of-n adjustment.
-1
Reverse the required difference order to before-minus-after; the mean changes sign while the sample SD and standard error do not.
A fitted line predicts fuel use from trip length observed only between 20 and 50 km. Its intercept is 6 liters. Which statement about the intercept is justified?
It is the average residual for the observed trips
It is the increase in fuel use per additional kilometer
It is the algebraic prediction at zero km, outside the observed range
It proves a zero-distance trip consumes exactly 6 liters
Answer: It is the algebraic prediction at zero km, outside the observed range
Locate x=0 relative to the observed explanatory-variable range.
The intercept has a formal meaning, but zero km was not represented by the observed trips.
Why an alternative fails: Treat an unsupported extrapolated prediction as a certain observed outcome.
Compare the other answer choices
It proves a zero-distance trip consumes exactly 6 liters
Treat an unsupported extrapolated prediction as a certain observed outcome.
It is the increase in fuel use per additional kilometer
Confuse the intercept with the slope.
It is the average residual for the observed trips
The intercept is a model coefficient, not an average prediction error.
Start with the lesson linked to an unfamiliar topic, try a focused set in the practice studio, then return to the review cards. Your practice progress stays in this browser.
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Foundation pilot, not complete AP syllabus coverage or an official exam simulation.
400 variants across 96 families; not independently calibrated item designs.
Practice includes numeric responses as learning exercises; official free responses require statistical reasoning and contextual justification.
No calibrated AP score prediction; independent educator review pending.
Broader inference procedures, authentic multi-focus free responses and full shared-stimulus exam sets need further development.
Foundation pilot, not full syllabus coverage or official simulation
Question variants are not independent question designs
Independent educator review pending
Evidence integrity and structure checks do not establish factual or audiovisual fidelity
Check the exam provider's current information for registration, test rules and official preparation materials. The exam guide collects the relevant official references.