AP Statistics 2025/2026 Exam Questions
and Answers | A+ Score Assured
How do you check if there is outliers? - 🧠 ANSWER ✔✔calculate IQR;
anything above Q3+1.5(IQR) or below Q1-1.5(IQR) is an outlier
If a graph is skewed, should we calculate the median or the mean? Why? -
🧠 ANSWER ✔✔median; it is resistant to skews and outliers
If a graph is roughly symmetrical, should we calculate the median or the
mean? Why? - 🧠 ANSWER ✔✔mean; generally is more accurate if the data
has no outliers
What is in the five number summary? - 🧠 ANSWER ✔✔Minimum, Q1,
Median, Q3, Maximum
,Relationship between variance and standard deviation? - 🧠 ANSWER
✔✔variance=(standard deviation)^2
variance definition - 🧠 ANSWER ✔✔the variance is roughly the average of
the squared differences between each observation and the mean
standard deviation - 🧠 ANSWER ✔✔the standard deviation is the square
root of the variance
What should we use to measure spread if the median was calculated? - 🧠
ANSWER ✔✔IQR
What should we use to measure spread if the mean was calculated? - 🧠
ANSWER ✔✔standard deviation
What is the IQR? How much of the data does it represent? - 🧠 ANSWER
✔✔Q3-Q1; 50%
How do you calculate standard deviation? - 🧠 ANSWER ✔✔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? - 🧠 ANSWER ✔✔
Categorical variables vs. Quantitative Variables - 🧠 ANSWER
✔✔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? - 🧠 ANSWER ✔✔No
Things to include when describing a distribution - 🧠 ANSWER ✔✔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 purpose of standardizing
a variable? - 🧠 ANSWER ✔✔Subtract the distribution mean and then divide
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, by standard deviation. Tells us how many standard deviations from the
mean an observation falls, and in what direction.
What effect does standardizing the values have on the distribution? - 🧠
ANSWER ✔✔shape would be the same as the original distribution, the
mean would become 0, the standard deviation would become 1
What is a density curve? - 🧠 ANSWER ✔✔a curve that (a) is on or above
the horizontal axis, and (b) has exactly an area of 1
Inverse Norm - 🧠 ANSWER ✔✔when you want to find the percentile:
invNorm (area, mean, standard deviation)
z - 🧠 ANSWER ✔✔(x-mean)/standard deviation
pth percentile - 🧠 ANSWER ✔✔the value with p percent observations less
than is
cumulative relative frequency graph - 🧠 ANSWER ✔✔can be used to
describe the position of an individual within a distribution or to locate a
specified percentile of the distribution
and Answers | A+ Score Assured
How do you check if there is outliers? - 🧠 ANSWER ✔✔calculate IQR;
anything above Q3+1.5(IQR) or below Q1-1.5(IQR) is an outlier
If a graph is skewed, should we calculate the median or the mean? Why? -
🧠 ANSWER ✔✔median; it is resistant to skews and outliers
If a graph is roughly symmetrical, should we calculate the median or the
mean? Why? - 🧠 ANSWER ✔✔mean; generally is more accurate if the data
has no outliers
What is in the five number summary? - 🧠 ANSWER ✔✔Minimum, Q1,
Median, Q3, Maximum
,Relationship between variance and standard deviation? - 🧠 ANSWER
✔✔variance=(standard deviation)^2
variance definition - 🧠 ANSWER ✔✔the variance is roughly the average of
the squared differences between each observation and the mean
standard deviation - 🧠 ANSWER ✔✔the standard deviation is the square
root of the variance
What should we use to measure spread if the median was calculated? - 🧠
ANSWER ✔✔IQR
What should we use to measure spread if the mean was calculated? - 🧠
ANSWER ✔✔standard deviation
What is the IQR? How much of the data does it represent? - 🧠 ANSWER
✔✔Q3-Q1; 50%
How do you calculate standard deviation? - 🧠 ANSWER ✔✔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? - 🧠 ANSWER ✔✔
Categorical variables vs. Quantitative Variables - 🧠 ANSWER
✔✔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? - 🧠 ANSWER ✔✔No
Things to include when describing a distribution - 🧠 ANSWER ✔✔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 purpose of standardizing
a variable? - 🧠 ANSWER ✔✔Subtract the distribution mean and then divide
COPYRIGHT©NINJANERD 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
STATEMENT. ALL RIGHTS RESERVED 3
, by standard deviation. Tells us how many standard deviations from the
mean an observation falls, and in what direction.
What effect does standardizing the values have on the distribution? - 🧠
ANSWER ✔✔shape would be the same as the original distribution, the
mean would become 0, the standard deviation would become 1
What is a density curve? - 🧠 ANSWER ✔✔a curve that (a) is on or above
the horizontal axis, and (b) has exactly an area of 1
Inverse Norm - 🧠 ANSWER ✔✔when you want to find the percentile:
invNorm (area, mean, standard deviation)
z - 🧠 ANSWER ✔✔(x-mean)/standard deviation
pth percentile - 🧠 ANSWER ✔✔the value with p percent observations less
than is
cumulative relative frequency graph - 🧠 ANSWER ✔✔can be used to
describe the position of an individual within a distribution or to locate a
specified percentile of the distribution
