Mathematics for IGCSE & O level - Statistical Diagrams (Section 6 - No. 47)
The lower quartile is to the 25th percentile, as the upper quartile is to the:
50th percentile
75th percentile
90th percentile
100th percentile
Maelezo
The upper quartile is the 75th percentile, just like the lower quartile is the 25th percentile.