What you’ll learn
Interpret measures of center.
Key idea
An isolated high value can pull the mean away from the main cluster; the median uses ordered position.
An isolated high value pulls the mean beyond the main cluster; neither mean nor median guarantees each individual's value.
Worked example
Classify examples and non-examples for the concept 'Interpret measures of center'.
Observed times are (4, 8, 12, 16, 84) minutes, mean 124/5, median 12. Classify 'the median better describes the typical four-reading cluster than the mean' using these data.
- Four readings cluster between 4 and 16, with an isolated high reading at 84 minutes.
- The mean 124/5 lies above that cluster; median 12 remains the ordered middle reading within it.
Answer: Example — four times lie in 4-16; the isolated 84 pulls the mean above that cluster.
Quick Check
Classify examples and non-examples for the concept 'Interpret measures of center'.
Observed times are (1, 2, 3, 4, 21) minutes, mean 31/5, median 3. Classify 'the median better describes the typical four-reading cluster than the mean' using these data.