Statistics · Spread & Distribution
Spread & Distribution
Mastery Quiz
20 challenging word problems covering IQR, standard deviation, box plots, and data classification.
⚡ Quick Memory Points
Range
Max − Min
⚠ Outlier sensitive!
IQR
Q3 − Q1 = middle 50%
✅ Outlier resistant
Population σ
√[Σ(x−μ)² / N]
÷ N (whole pop.)
Sample s
√[Σ(x−x̄)² / (n−1)]
÷ n−1 (sample)
Skew Left
mean < median
tail goes LEFT
Outlier Rule
↑ SD dramatically
IQR stays stable
Quiz Complete 🎉
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