AP Stats Formula Sheet: What Is on It and How to Use It

You get a formula sheet and three statistical tables on the AP Statistics exam, and they are available on both the multiple-choice and free-response sections. The sheet covers descriptive statistics, probability, sampling distributions, and the general structure of inference. It does not include conditions, interpretations, or vocabulary, which is exactly what the free-response rubrics reward.

This guide covers the reference information for the revised AP Statistics exam (first given in May 2027), what is missing from it, and how to practice so the sheet speeds you up.

What is the AP Statistics exam format now?

AP Statistics was revised for the 2026-27 school year, and the exam is now fully digital in the Bluebook app.

Calculators are permitted. Check College Board's calculator policy for approved models. Because responses are typed, the reference packet now also includes guidance on entering statistical notation with a keyboard.

What is on the AP Stats formula sheet?

College Board's reference packet, posted on AP Central and in the Bluebook test preview, has three main parts: digital entry information, the formulas, and the tables.

I. Descriptive statistics

• The sample mean
• The sample standard deviation (with n − 1 in the denominator)
• The least-squares regression line, written as ŷ = a + bx

II. Probability and distributions

• The addition rule: P(A ∪ B) = P(A) + P(B) − P(A ∩ B)
• Conditional probability: P(A | B) = P(A ∩ B) / P(B)
• Mean (expected value) and standard deviation of a discrete random variable
• The binomial probability formula, plus the binomial mean (np) and standard deviation

III. Sampling distributions and inferential statistics

• The general form of a standardized test statistic: (statistic − parameter) / (standard error of the statistic)
• The general form of a confidence interval: statistic ± (critical value)(standard error of the statistic)
• The chi-square statistic
• Mean, standard deviation, and standard error for one-sample and two-sample proportions, including the pooled standard error
• Mean, standard deviation, and standard error for one-sample and two-sample means

The tables

You can use either the tables or your calculator. Most students use the calculator for speed, but knowing how to read Table B matters for critical values like t* when your calculator does not have invT.

What is NOT on the AP Stats formula sheet?

This is the part to study hardest. The sheet tells you how to compute. It never tells you what the result means.

Inference conditions

None of the conditions for inference are on the sheet. You need to know them for every procedure:

1. Random: the data come from a random sample or a randomized experiment.
2. Independence (10% condition): when sampling without replacement, the sample is less than 10% of the population.
3. Normal/large sample: for proportions, expected successes and failures are at least 10; for means, the population is approximately normal or the sample is large enough (n ≥ 30 is the common guideline), or a graph of the sample shows no strong skew or outliers.

For a procedure-by-procedure summary, use our AP Statistics inference cheat sheet.

Interpretations

• What a confidence interval and a confidence level mean, in context
• What a p-value means
• How to state a conclusion that links the p-value to the significance level and answers the question in context
• What slope, y-intercept, r, and r² mean in context

Vocabulary and concepts

• Type I and Type II errors, and power
• Experimental design terms: random assignment, control group, blocking, blinding, placebo, and confounding
• Sampling methods and bias: simple random, stratified, cluster, and systematic samples; undercoverage, nonresponse, and response bias
• Independence versus mutually exclusive events

How do you use the formula sheet on the free response?

The revised exam has four free-response questions, and one focuses specifically on inference. Here is how to use the sheet on an inference question.

1. Name the procedure. For example, "one-sample t interval for a population mean."
2. Define the parameter in context. "μ = the true mean commute time, in minutes, for all employees at this company."
3. Check conditions in writing. The sheet will not remind you, so build the habit.
4. Pull the standard error from Section III. Match it to your situation: one or two samples, proportions or means.
5. Plug into the general form. Statistic ± (critical value)(standard error) for an interval, or (statistic − parameter)/(standard error) for a test.
6. Conclude in context. Interpret the interval or compare the p-value to α and state your conclusion about the parameter.

Worked example: a one-proportion interval

A random sample of 400 students at a large school finds that 248 prefer a later start time. Construct a 95% confidence interval for the true proportion.

1. p̂ = 248/400 = 0.62.
2. Conditions: random sample; 400 is less than 10% of a large school's students; successes (248) and failures (152) are both at least 10.
3. From the sheet, the standard error is the square root of p̂(1 − p̂)/n = the square root of (0.62)(0.38)/400 ≈ 0.0243.
4. For 95% confidence, z* = 1.96.
5. Interval: 0.62 ± 1.96(0.0243) = 0.62 ± 0.048, or about (0.572, 0.668).
6. Interpretation: we are 95% confident that the interval from 0.572 to 0.668 captures the true proportion of all students at this school who prefer a later start time.

The sheet supplied step 3. Steps 1, 2, 4, 5, and 6 all came from you, and most of the rubric points live there.

How should you study with the formula sheet?

1. Download the current version from AP Central. The revised course has an updated reference packet, so do not rely on an older printout.
2. Use it on every homework set. You want to find any formula in seconds.
3. Make a separate "not on the sheet" study page. List conditions, interpretation templates, and design vocabulary, and review it weekly.
4. Practice typing notation. Since the exam is digital, rehearse writing p̂, x̄, and μ with the keyboard options described in the packet.
5. Score practice FRQs with official rubrics. Our AP Stats FRQ guide explains what each question type rewards.

Then check where your practice scores land with the AP Statistics score calculator. Score cutoffs shift each year, so treat it as an estimate. For a complete plan, see how to get a 5 on AP Statistics.

How Ivystar can help

Ivystar tutors teach you how to turn a formula into full-credit work: naming the procedure, checking conditions, and writing conclusions in context. Our AP Exam Prep program offers private 1-on-1 or small-group sessions, and 86% of our students finish with an A or higher in the class. Book a free 20-minute strategy call to map out your prep.