Concept · 4 steps · NESA MA4-DAT-C-02

The Effect of Individual Data Points

One stray number can tip a whole summary. Learn how a single value — an outlier — shoves the mean and range about while the median barely flinches, and how to pick the average that tells the truth.

1Where it comes fromDrag one dot far out and watch the mean chase it while the median holds. 2How to do itRecompute the mean, median and range after adding or removing a value. 3Where it gets trickyOutliers swing the mean and range hard — the median and mode shrug. 4Out in the wildA dodgy "average wage", picking the honest average, and shifting a mean on purpose.

← This concept rests on

Mean, Median, Mode and Range

→ It unlocks

Displaying Data in Graphs
Analysing Datasets and Drawing Conclusions