quartile
UK[ˈkwɔːtaɪl]US[ˈkwɔːrtaɪl]
n
Any of the three values that divide a set of ranked data into four equal parts.
n
Each of the four groups resulting from such a division.
Morpheme Breakdown
quart
ile
quart
fourth
ile
relating to
Etymology
The word 'quartile' is a modern statistical term built directly from classical Latin components. Its core, 'quart-', originates from the Latin quartus, meaning "fourth," which itself derives from the Proto-Indo-European root kʷetwer-, the source for the number four across many languages. The suffix '-ile', from Latin -ilis, is a common adjectival ending meaning "pertaining to." Thus, the literal construction means "pertaining to a fourth." This logic was applied in statistics to name the points that divide a distribution into four equal parts, with the term first appearing in English in the late 19th century to describe these specific positional measures.
Analysis
Structure: quart (fourth) + ile (relating to)
- 'quart': From Latin quartus, meaning "fourth".
- 'ile': A suffix from Latin -ilis, forming adjectives and nouns meaning "relating to" or "capable of".
Examples
The first quartile marks the point below which 25% of the data falls.
Students scoring in the top quartile on the test will receive a certificate.
The interquartile range, calculated from the first and third quartiles, shows the spread of the middle 50% of values.