Question

Which values in this data set are outliers?

48, 52, 56, 64, 61, 20, 48, 51, 58, 48, 78



Value Outlier Not Outlier
20


48


64


78


yes or no

Answer 1

Sort: 20, 48, 48, 48, 51, 52, 56, 58, 61, 64, 78
Median = 52, Q1 = 48, Q3 = 61 → IQR = 13
Lower fence = 48 − 1.5(13) = 28.5
Upper fence = 61 + 1.5(13) = 80.5

Any value <28.5 or >80.5 is an outlier. Thus:

- 20 — Yes (outlier)
- 48 — No
- 64 — No
- 78 — No