# Summarizing quantitative data

AP Stats: UNC (BI), UNC‑1 (EU), UNC‑3 (EU)

## Measuring center in quantitative data

AP Stats: UNC (BI), UNC‑1 (EU), UNC‑1.I (LO), UNC‑1.I.1 (EK), UNC‑1.I.2 (EK), UNC‑1.I.3 (EK)
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Statistics intro: Mean, median, & modeMean, median, & mode exampleMedian in a histogram
Practice
Calculating the meanGet 3 of 4 questions to level up!
Calculating the medianGet 3 of 4 questions to level up!
Calculating mean and median from data displaysGet 3 of 4 questions to level up!

## More on mean and median

AP Stats: UNC (BI), UNC‑1 (EU), UNC‑1.I (LO), UNC‑1.I.2 (EK), UNC‑1.K (LO), UNC‑1.K.2 (EK), UNC‑1.M (LO), UNC‑1.M.2 (EK)
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Mean as the balancing pointMissing value given the meanImpact on median & mean: increasing an outlierImpact on median & mean: removing an outlierEstimating mean and median in data displays
Practice
Missing value given the meanGet 3 of 4 questions to level up!
Estimating mean and median in data displaysGet 3 of 4 questions to level up!

## Measuring spread in quantitative data

AP Stats: UNC (BI), UNC‑1 (EU), UNC‑1.J (LO), UNC‑1.J.1 (EK), UNC‑1.J.2 (EK), UNC‑1.J.3 (EK), UNC‑1.K (LO), UNC‑1.K.2 (EK)
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Interquartile range (IQR)Sample varianceSample standard deviation and biasVisually assessing standard deviationMean and standard deviation versus median and IQR
Practice
Interquartile range (IQR)Get 3 of 4 questions to level up!
Sample standard deviationGet 3 of 4 questions to level up!
Visually assessing standard deviationGet 3 of 4 questions to level up!

## More on standard deviation (optional)

AP Stats: UNC (BI), UNC‑1 (EU), UNC‑1.J (LO), UNC‑1.J.3 (EK), UNC‑3 (EU), UNC‑3.I (LO), UNC‑3.I.1 (EK)
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Review and intuition why we divide by n-1 for the unbiased sample varianceWhy we divide by n - 1 in variance Simulation showing bias in sample varianceSimulation providing evidence that (n-1) gives us unbiased estimateUnbiased estimate of population variance

## Box and whisker plots

AP Stats: UNC (BI), UNC‑1 (EU), UNC‑1.K (LO), UNC‑1.K.1 (EK), UNC‑1.L (LO), UNC‑1.L.1 (EK), UNC‑1.L.2 (EK)
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Worked example: Creating a box plot (odd number of data points)Worked example: Creating a box plot (even number of data points)Reading box plotsInterpreting box plotsJudging outliers in a dataset
Practice
Creating box plotsGet 3 of 4 questions to level up!
Reading box plotsGet 3 of 4 questions to level up!
Interpreting quartilesGet 3 of 4 questions to level up!
Identifying outliersGet 3 of 4 questions to level up!