A statistical measure indicating the value below which a given percentage of observations in a dataset fall. For example, if a plant’s growth rate is in the 90th percentile, it performed better than 90% of the plants in the comparison group.
- Median: The 50th percentile.
- Quartile: Divides data into four equal groups (25th, 50th, 75th, and 100th percentiles).
- Rank: A position relative to others in a dataset.
- Percentile Rank: The percentage of observations that fall at or below a particular value.
Quartiles divide a dataset into four equal groups, each containing 25% of the observations.
- First Quartile (Q1) – The 25th percentile
- 25% of values fall below this point.
- 75% of values fall above it.
- Second Quartile (Q2) – The 50th percentile (the median)
- Half of all values fall below this point.
- Half fall above it.
- Third Quartile (Q3) – The 75th percentile
- 75% of values fall below this point.
- 25% fall above it.
- Fourth Quartile (Q4) – The top 25% of values
- Contains values above the 75th percentile, up to the highest value in the dataset.
See Also
