Outliers and Their Effect
Aligned to S-ID.A.3 — Common Core State Standards for Mathematics.
What this lesson teaches
An outlier is a value far from the rest of the data. Outliers pull the mean toward themselves and inflate the range, while the median stays much more stable.
Worked example
The data 4, 5, 6, 7, 100 has an outlier at 100. Its mean is 122 / 5 = 24.4, far above most values, but its median is the middle value 6, which better represents the data.
Practice questions
- Identify the outlier in 12, 13, 14, 15, 92.
- Does the mean or the median change more when an outlier is added? Explain.
- Find the median of 3, 4, 5, 6, 80.
Watch the lesson
Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.
▶ Watch this lessonEn español
Valores Atípicos y su Efecto
Un valor atípico es un valor lejano al resto de los datos. Los valores atípicos jalan la media hacia ellos e inflan el rango, mientras que la mediana se mantiene mucho más estable.
Ejemplo: Los datos 4, 5, 6, 7, 100 tienen un valor atípico en 100. Su media es 122 / 5 = 24.4, muy por encima de la mayoría, pero su mediana es el valor central 6, que representa mejor los datos.
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