AP Statistics 2026 | Study
Guide, Practice Questions
& Exam Review
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Updated 2026 Questions and Answers
100% Verified Exam Prep and Comprehensive
Rationales
Included
, What is in the five number summary? Minimum, Q1, Median, Q3, Maximum
Relationship between variance and standard deviation? variance=(standard deviation)^2
variance definition the variance is roughly the average of the squared differences between each
observation and the mean
standard deviation the standard deviation is the square root of the variance
What should we use to measure spread if the median was IQR
calculated?
What should we use to measure spread if the mean was standard deviation
calculated?
What is the IQR? How much of the data does it Q3-Q1; 50%
represent?
How do you calculate standard deviation? 1. Type data into L1
2. Find mean with 1 Variable Stats
3. Turn L2 into (L1-mean)
4. Turn L3 into (L2)^2
5. Go to 2nd STAT over to MATH, select sum(
6. Type in L3
7. multiply it by (1/n-1)
8. Square root it
What is the formula for standard deviation?
Categorical variables vs. Quantitative Variables Categorical: individuals can be assigned to one of several groups or categories
Quantitative: takes numberical values
If a possible outlier is on the fence, is it an outlier? No
Things to include when describing a distribution Center (Mean or Median), Unusual Gaps or Outliers, Spread (Standard Deviation
or IQR), Shape (Roughly Symmetric, slightly/heavily skewed left or right, bimodal,
range)
Explain how to standardize a variable. What is the Subtract the distribution mean and then divide by standard deviation. Tells us how
purpose of standardizing a variable? many standard deviations from the mean an observation falls, and in what
direction.
What effect does standardizing the values have on the shape would be the same as the original distribution, the mean would become 0,
distribution? the standard deviation would become 1
What is a density curve? a curve that (a) is on or above the horizontal axis, and (b) has exactly an area of 1
Guide, Practice Questions
& Exam Review
|Graded A+ | Guaranteed
success|
Updated 2026 Questions and Answers
100% Verified Exam Prep and Comprehensive
Rationales
Included
, What is in the five number summary? Minimum, Q1, Median, Q3, Maximum
Relationship between variance and standard deviation? variance=(standard deviation)^2
variance definition the variance is roughly the average of the squared differences between each
observation and the mean
standard deviation the standard deviation is the square root of the variance
What should we use to measure spread if the median was IQR
calculated?
What should we use to measure spread if the mean was standard deviation
calculated?
What is the IQR? How much of the data does it Q3-Q1; 50%
represent?
How do you calculate standard deviation? 1. Type data into L1
2. Find mean with 1 Variable Stats
3. Turn L2 into (L1-mean)
4. Turn L3 into (L2)^2
5. Go to 2nd STAT over to MATH, select sum(
6. Type in L3
7. multiply it by (1/n-1)
8. Square root it
What is the formula for standard deviation?
Categorical variables vs. Quantitative Variables Categorical: individuals can be assigned to one of several groups or categories
Quantitative: takes numberical values
If a possible outlier is on the fence, is it an outlier? No
Things to include when describing a distribution Center (Mean or Median), Unusual Gaps or Outliers, Spread (Standard Deviation
or IQR), Shape (Roughly Symmetric, slightly/heavily skewed left or right, bimodal,
range)
Explain how to standardize a variable. What is the Subtract the distribution mean and then divide by standard deviation. Tells us how
purpose of standardizing a variable? many standard deviations from the mean an observation falls, and in what
direction.
What effect does standardizing the values have on the shape would be the same as the original distribution, the mean would become 0,
distribution? the standard deviation would become 1
What is a density curve? a curve that (a) is on or above the horizontal axis, and (b) has exactly an area of 1
