6: Grouping with Z-Scores
Students convert raw scores to z-scores, use z-score thresholds to classify observations into groups, and identify statistical outliers using standard deviation cutoffs.
Lowest Biodiversity Scores Using Z-Scores
Click to show Lowest Biodiversity Scores Using Z-Scores example problem
Ecologists assess biodiversity across four Chicago-area villages by calculating Z-scores for plant diversity, insect diversity, and bird diversity. Based on the data provided below, which village shows the HIGHEST level of biodiversity overall?
| Village | Plant Z-Score |
Insect Z-Score |
Bird Z-Score |
Total Z-Score |
|---|---|---|---|---|
| Bensenville | 1.99 | 0.38 | -0.47 | 1.90 |
| Glenview | -1.65 | 0.09 | 1.12 | -0.40 |
| Highland Park | -0.97 | -1.09 | -0.19 | -2.30 |
| Naperville | 0.47 | 1.80 | 1.60 | 3.90 |