AP Statistics practice test
Practice questions for the five units of the revised AP Statistics course: one-variable data and study design, probability and random variables, inference for proportions, inference for means, and regression. Answer in your browser and read why each answer is right.
Question 1 of 28
A data set of house prices has a few very expensive homes. Which measure of center is least affected by them?
Question 2 of 28
A distribution is strongly skewed to the right. How do the mean and median usually compare?
Question 3 of 28
Test scores have mean 75 and standard deviation 5. What is the z-score for a score of 85?
Question 4 of 28
For a roughly normal distribution, about what percent of values fall within 2 standard deviations of the mean?
Question 5 of 28
What allows a study to conclude that a treatment causes a change in the response?
Question 6 of 28
A radio host asks listeners to call in with their opinion on a new law. What is the main problem?
Question 7 of 28
A researcher splits a school into grades and takes a simple random sample from each grade. This is a
Question 8 of 28
P(A) = 0.5, P(B) = 0.4 and P(A and B) = 0.2. What is P(A or B)?
Question 9 of 28
Of 200 students, 80 play a sport, and 30 of those 80 are also in the band. A student who plays a sport is chosen at random. What is the probability they are in the band?
Question 10 of 28
Events A and B are independent, with P(A) = 0.3 and P(B) = 0.6. What is P(A and B)?
Question 11 of 28
X is binomial with n = 10 and p = 0.3. What is the mean of X?
Question 12 of 28
A game pays $10 with probability 0.2; otherwise you lose $3. What is the expected value of one play?
Question 13 of 28
Which situation fits a binomial setting?
Question 14 of 28
What does "95% confident" mean for a confidence interval for a proportion?
Question 15 of 28
How do you interpret a p-value of 0.03?
Question 16 of 28
What is a Type I error?
Question 17 of 28
Keeping the confidence level the same, what happens to a confidence interval if the sample size increases?
Question 18 of 28
What is the large counts condition for a one-sample z interval for a proportion?
Question 19 of 28
A random sample of adults is classified by age group and by preferred news source. Which test checks whether the two variables are associated?
Question 20 of 28
What does the Central Limit Theorem say?
Question 21 of 28
If the sample size is multiplied by 4, the standard deviation of the sample mean is
Question 22 of 28
Students take a test before and after a tutoring program. Which procedure should be used?
Question 23 of 28
Why do we use a t distribution rather than z when making inferences about a mean?
Question 24 of 28
The correlation between two variables is r = −0.9. What does this mean?
Question 25 of 28
The least-squares line predicts ŷ = 12 for a point whose actual value is y = 10. What is the residual?
Question 26 of 28
A regression line is ŷ = 50 + 3x, where x is hours studied and ŷ is the predicted test score. How should the slope be interpreted?
Question 27 of 28
A regression has r² = 0.64. What does this mean?
Question 28 of 28
A residual plot shows a clear curved pattern. What should you conclude?
AP Statistics key terms
Flip through these flashcards to review the terms that come up most often. Use the arrow keys or click a card to flip it.
| Resistant measures | Median and IQR are resistant to outliers; mean and standard deviation are not. |
| z-score | z = (x − mean) / standard deviation |
| Empirical rule | 68% within 1 SD, 95% within 2, 99.7% within 3 (normal distributions) |
| Random sampling vs. random assignment | Sampling: generalize to the population. Assignment: conclude cause and effect. |
| Stratified vs. cluster sample | Stratified: sample within every group. Cluster: randomly pick whole groups. |
| General addition rule | P(A or B) = P(A) + P(B) − P(A and B) |
| Conditional probability | P(A | B) = P(A and B) / P(B) |
| Binomial mean and SD | μ = np, σ = √(np(1 − p)) |
| Confidence interval | statistic ± (critical value) × (standard error) |
| p-value | Probability of a result at least as extreme as observed, assuming H₀ is true. |
| Type I and Type II errors | Type I: reject a true H₀. Type II: fail to reject a false H₀. |
| Central Limit Theorem | For large n, x̄ is approximately normal, with SD σ/√n. |
| Matched pairs | Two related measurements per subject; analyze the differences. |
| Residual | Observed y − predicted ŷ |
| r² | Fraction of the variation in y explained by the linear model. |
See all 15 cards
Resistant measuresMedian and IQR are resistant to outliers; mean and standard deviation are not.
z-scorez = (x − mean) / standard deviation
Empirical rule68% within 1 SD, 95% within 2, 99.7% within 3 (normal distributions)
Random sampling vs. random assignmentSampling: generalize to the population. Assignment: conclude cause and effect.
Stratified vs. cluster sampleStratified: sample within every group. Cluster: randomly pick whole groups.
General addition ruleP(A or B) = P(A) + P(B) − P(A and B)
Conditional probabilityP(A | B) = P(A and B) / P(B)
Binomial mean and SDμ = np, σ = √(np(1 − p))
Confidence intervalstatistic ± (critical value) × (standard error)
p-valueProbability of a result at least as extreme as observed, assuming H₀ is true.
Type I and Type II errorsType I: reject a true H₀. Type II: fail to reject a false H₀.
Central Limit TheoremFor large n, x̄ is approximately normal, with SD σ/√n.
Matched pairsTwo related measurements per subject; analyze the differences.
ResidualObserved y − predicted ŷ
r²Fraction of the variation in y explained by the linear model.
About the AP Statistics exam
- The course was revised for 2026–27: nine units became five. Geometric distributions, combining random variables, the chi-square goodness-of-fit test and inference for slope were removed.
- Section I: 42 multiple-choice questions in 90 minutes, 50% of the score. Each question now has four answer choices, and some questions share a prompt.
- Section II: 4 free-response questions in 90 minutes, 50% of the score, each worth 10 points. One is an inference question (a hypothesis test or confidence interval).
- The exam is fully digital in the Bluebook app, and a calculator is allowed throughout.
Questions
Are these real AP Statistics exam questions?
No. They are original practice questions written to match the topics and style of the AP Statistics course. For released exam questions, see AP Central from the College Board.
Is it free?
Yes. The practice questions and flashcards on this page are free, with no sign-up.
Can I get more practice questions?
Yes. Paste your own notes or upload a textbook chapter into the quiz maker and it writes a new practice quiz from that material, with explanations for every answer.
Study your own notes
Turn your AP Stats notes into a study guide, a practice quiz or flashcards.
Related practice tests: AP Precalc · AP Calc AB · AP Calc BC · all AP practice tests