Subjects › Probability & Statistics
Describing data
Mean, median, spread, and when each one lies to you.
The idea
The mean is not 'the average' — it is one average with a specific weakness. Every question here is really asking: does this summary survive contact with this shape of data?
Lesson
No lesson built yet. The worked solutions below are the material it would be assembled from.
Questions (5)
| Question | Type | Difficulty | Drift | Accuracy |
|---|---|---|---|---|
| Find the median of: 3, 7, 2, 9, 4 | numeric | Introductory -1.61 | -0.11 | 100% (1) |
| Find the median of: 10, 4, 8, 6 | numeric | Easy -0.70 | — | — (0) |
| Nine employees earn £30k each; the founder earns £930k. Which summary best describes a typical salary here? | mcq | Moderate 0.00 | — | — (0) |
| Two datasets both have a mean of 50. Dataset A has a standard deviation of 2; dataset B has 20. Describe how t… | short | Hard 0.90 | — | — (0) |
| A dataset's mean is well above its median. What does this suggest about its shape? | mcq | Hard 1.20 | — | — (0) |