Reach your peak.
A quick run every day, an explanation for every question, and full-length tests on official timing.
Full-length tests
98 questions across four modules, in the digital SAT’s order and on its timing, with a highlighter, a question map and a timer you can see.
How it works
A quick run with three hearts. String right answers together and the questions get harder and the points multiply.
Every question is tagged by domain and skill, and every answer comes with an explanation.
Practice any single skill at any difficulty, or just the questions you got wrong.
Come back tomorrow and climb. Progress shows your accuracy and your strongest skills.
Every question is tagged by section, domain, skill and difficulty, so you can practice exactly what you need. Full tests run like test day: two Reading & Writing modules, a break, then two Math modules.
9 easy, 9 medium, 9 hard and 9 challenging questions free every day, each with a full explanation. Filter by section, domain, skill and difficulty. Resets at midnight Central Time.
Take any test on official timing, extended 1.5× time, or untimed to focus purely on accuracy.
Four modules in official order. The second module of each section adapts to how you did on the first.
1,023 essential SAT words. Browse the list, flip flashcards, or quiz yourself.
Accuracy across daily practice and full tests, your strongest skills, and the ones that need the most help.
PEAK Survivor, Hole and Peak Defense: three games powered by SAT practice questions.
Explanations
Not just the right letter: how to get there, and why the tempting answer is wrong.
A store raises the price of a jacket by 20%. Later, it lowers the new price by 20%. The final price is what percent of the original price?
Check with $100: $100→then$120→then$96
Up 20% means × 1.20. Down 20% means × 0.80.
1.20 × 0.80 = 0.96
The final price is 96% of the original. That’s B.
The 20% cut is taken from the higher price, so it removes more than the 20% increase added.
Test day
Every Peakscor full test follows this order. In the standard tests, the second module of each section adapts to how you did on the first.
27 questions32 min
27 questions32 min
10 min
22 questions35 min
22 questions35 min
98 questions · 2 hr 14 min of testing, plus the break
Plans
The free plan is the real thing, not a trial. Pro removes the limits. Peak adds the full course and a plan to test day.
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$20a month, or $200 a year
$29a month, or $280 a year
Prices in US dollars. Cancel anytime.
FAQ
The Daily, plus 36 practice questions every day: 9 easy, 9 medium, 9 hard and 9 challenging, each with a full explanation. Full-length Test A, Challenge Test 1 and all 1,023 vocabulary words are free too, as are the 20-question diagnostic, each Learn module’s overview and first lesson, and PEAK Survivor’s first map. No card needed.
Pro is $20 a month or $200 a year: unlimited practice with no daily limit, plus every full-length test and Challenge test, and every game map and level. Peak is $29 a month or $280 a year: everything in Pro, plus the full Learn course and Peak Plan. Cancel anytime from your account.
98 questions across four modules, in the digital SAT’s order: Reading & Writing Module 1 and Module 2 (27 questions each), a 10-minute break, then Math Module 1 and Module 2 (22 questions each). On official timing that’s 2 hr 14 min of testing. You get estimated section scores and a total at the end.
Yes. In the standard full-length tests, Module 2 of each section is the harder version if you get 60% or more of Module 1 right, and the easier version if you don’t. Challenge tests use the hardest material throughout.
Official timing, extended 1.5× time, or untimed, on every test, including the free ones. Extended time allows 48 minutes for each Reading & Writing module and about 52 for each Math module. Untimed removes the clock so you can focus on accuracy.
A quick run with three hearts. Each right answer builds your streak: the questions get harder as it grows, and your points multiply (×2 from three in a row, ×3 from six). A miss costs a heart and drops you back to easy. Best is your longest streak.
Every day at midnight Central Time. You get a fresh 9 easy, 9 medium, 9 hard and 9 challenging.
No. Peakscor is an independent SAT practice tool, not affiliated with the College Board. Scores shown are estimates.
Free, no card.
Inference and margin of error · Lesson 2
A random sample gives an estimate, but a different random sample would give a slightly different one. The margin of error describes how far the estimate could plausibly be from the true population value.
Subtract it and add it. If a survey of a random sample of a city's adults estimates that 52% of them favor a later school start time, with a margin of error of 3%, the interval runs from to , in percent. For a percent, the margin is in percentage points: 3% here means 3 points, not 3% of 52.
The SAT's wording for what this means: it is plausible that between 49% and 55% of all the city's adults favor a later start. Values inside the interval are plausible. Values outside it are less plausible, and the further outside, the less plausible.
The same reading works for a mean. If a random sample of a school's students spends a mean of 6.2 hours a week on homework, with a margin of error of 0.4 hours, it is plausible that the mean for all the school's students is between 5.8 and 6.6 hours. That says nothing about how long any one student spends.
A margin of error is reported at a confidence level, often 95%, so even the interval isn't a guarantee. What the SAT asks you to know is what the interval is about: the population's percent or mean, as a range of plausible values. The margin covers only the chance variation of random sampling (which members happened to be picked), not bias from a nonrandom sample or a misleading question.
| Supported | Not supported |
|---|---|
| The true value is plausibly in the interval | The true value is exactly the estimate |
| A claim about the population's percent or mean | A claim about individual members |
| Plausible, reasonable to conclude | Certain, proven, guaranteed |
| The margin covers chance variation from random sampling | The margin covers bias from a nonrandom sample or a misleading question |
Which of the following is the most appropriate conclusion about all registered voters in the city?
Which of the following is the most appropriate conclusion?
Exactly 58% or the true mean is 27 minutes states the estimate as a fact. The true value is one number you don't know. The margin of error gives a range of plausible values for it, and the estimate is only the middle of that range.
An interval for a mean describes the population's average, not where each member falls. Most students spend between 5.8 and 6.6 hours on homework is a different claim, and the survey doesn't support it.
Certain, proves and guarantees claim more than a random sample can show. A correct conclusion never overclaims. It may hedge with words such as plausible, reasonable to conclude or likely, or it may say what the data don't show. Careful words alone don't make a choice right, though: many wrong choices use them too. When a choice states a value for the population, the group, the quantity (a mean or percent, not individual values) and the numbers also have to match what was sampled, unless the choice is pointing out that the sample is biased.
Desmos isn't faster here. These are reading questions: the arithmetic is one subtraction and one addition, and the real work is matching the conclusion to what the interval describes.
If the interval has to become a count, such as 54% to 62% of 15,000 voters, you can type 0.5415000 and 0.6215000 on two lines, but mental math or any calculator is just as quick.
Choose a section, then practice a whole domain or drill a single skill.
Each test mirrors the digital SAT: 98 questions across four modules, 2 hr 14 min on official timing.
Same 98-question format, but every question is drawn from the toughest SAT material: Challenging-tier math throughout and the hardest reading.
Study the classic SAT vocabulary list. Browse, flip flashcards, or quiz yourself.
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