Today is rung 3 of 5 on this topic
Statistics: mean, median, spread and what a graph hides
Can do: Calculates mean, median and range, and chooses which measure describes a data set honestly.
Why it matters
Averages are the most misused numbers in public life. Knowing when a mean lies is a genuine life skill.
What it looks like when it's wobbly
Uses the mean for everything and never notices that one huge value has dragged it away from the typical value.
⏱️ Two-minute check
"Six people earn $30k and one earns $500k. What's the mean? The median? Which describes this group better?"
Solid looks like: Median chosen, with an explanation about the outlier.
The full activity for this topic · 20 minutes
Whose Average Is It?
- 1Collect a real data set of ten values.
- 2Calculate mean, median, mode and range.
- 3Add one enormous outlier and recalculate. Watch which measure moves.
- 4Draw a dot plot to see the shape of the data.
- 5Find a real headline using an average and ask which measure they used, and why.
If it's too hard
Five values, mean and range only.
If it's too easy
Compare two data sets with the same mean and different spreads, and describe the difference.
Say this
"The mean says one thing and the median says another. Which one describes a typical person here?"