1Each of four equal groups into which a population can be divided according to the distribution of values of a particular variable.
- ‘The initial categories were created by stratifying lesions into quartiles according to size.’
- ‘The school is one of several elementary schools within a district that is in the bottom quartile when fourth grade standardized test scores and passage rates are compared throughout the state.’
- ‘White women were older, smoked more, and were less likely to have dietary calcium intakes in the lowest quartile of distribution than black and Hispanic women.’
- ‘Children in the upper quartile of the blood-lead-concentration distribution donated another blood sample in February 1993.’
- ‘The resulting distributions for men and women were divided into quartiles.’
- 1.1 Each of the three values of the random variable that divide a population into four groups.
- ‘Every measurement was first divided by its plate's quartile and then multiplied by the average quartile of the respective experiment.’
- ‘Here we would like to estimate the quartiles of the distribution of age at leaving home, within categories of covariates.’
- ‘Disparities in college enrollment by family income quartiles are almost as large today as they were thirty years ago.’
- ‘Simple quartiles cannot be defined in interval variables unless their boundaries chance to fall at interval boundaries.’
- ‘We calculate medians and quartiles of the age at leaving home by sex and race, using a fitted curve derived from a logit regression model.’
Late 19th century: from medieval Latin quartilis, from Latin quartus fourth.
We take a look at several popular, though confusing, punctuation marks.