The phrase "and a quartile of" is correct and usable in written English.
It can be used in statistical contexts when discussing data distribution and the division of data into four equal parts.
Example: "The results showed that the median score fell between the second and third quartile, indicating a significant variation in performance."
Alternatives: "and a quarter of" or "and one-fourth of".
First, we converted the NAI or testing scores to ordered categorical variables in four levels (excellent, good, not bad, and bad), each corresponding to a quartile of distribution of the NAI or testing score.
After adjusting for age, energy intake, smoking habit, alcohol drinking, physical activity and salt intake, a low adherence to HDI and a lowest quartile of AI-84 score were associated with a significantly higher prevalence of untreated hypertension, with an OR of 3.33 (95% CI 1.39 to 7.94, p=0.007) and 2.23 (1.09 to 4.53, p=0.027), respectively.
The distribution of CV-CV' of bacterial hydrolases is characterized by an average of 0.42 and a first quartile of -0.18.
Medium- sized hydrolases have an average of CV-CV' of 0.98 and a first quartile of 0.54.
Large hydrolases have an average of CV-CV' of 0.93 and a first quartile of 0.61, they are in general predicted to be highly insoluble.
Small hydrolases have an average of CV-CV' of 0.48 and a first quartile of -0.17, thus more than 25%% of small hydrolases are predicted to be soluble in E. coli.
After adjusting for age, total energy intake, smoking habit, alcohol drinking, physical activity and salt intake (model 2), low adherence to HDI was significantly associated with the prevalence UHT with an OR of 3.33 (95% CI 1.39 to 7.94, p=0.007), and a lowest quartile of AI-84 score was significantly associated with a higher prevalence of UHT with an OR of 2.23 (95% CI 1.09 to 4.53, p=0.027).
In the case of family income, we used two approaches to detecting non-linearity: a semilog model in which ECEC use was regressed on the log of income and a quartile model in which ECEC use was regressed on three dummy variables indicating family income quartiles (with the wealthiest quartile excluded as the comparison group).
Per questionnaire, the number of quotations would have been between 1 and 66, with an arithmetic mean of 10.41, a lower quartile of 3, a median of 6 and an upper quartile of 12 13; the mode would have been 2. In the 64 questionnaires (representing the same number of references) actually sent, 709 quotations (91% of all quotations) were included in the total.
The children in group two (children with a hip disorder) had a median score of 4 (1-5) with a lower quartile of 3.5 and an upper quartile of 5 whereas the healthy children all scored 5.
Referring to Figure 4, the lower, middle-lower, middle-upper, and upper boxes represent the lower quartile, mid-lower quartile, mid-upper quartile, and upper quartile of a distribution.
