The score of the student 'a quarter of the way from the top'. A quarter of the students in a tariff table will score at least this; the other three quarters will score no more than this.
(Q3) A value that exceeds the values for no more than three quarters of the individuals and is exceeded by the values of no more than one quarter of the individuals. cf. lower quartile.
The 75th percentile, calculated by ordering the data from smallest to largest and finding the value which lies 75% of the way up through the data. Box and whisker plots are a graphical display of a sample in terms of its quartiles.