In describing the relationship between percentiles and quartiles of a data set, is it accurate to say that the percentiles belonging to the first quartile range from the zeroth to the 24th percentile?
As such, the value at the 25th percentile marks the boundary of the first quartile; it belongs to the second quartile.
Visually, this could be represented as:
Q1 | Q2 | Q3 | Q4
0-24 | 25-49 | 50-74 | 75-99