The median of the upper half of the data set is known as Upper Quartile. And the Interquartile Range is. The IQR describes the middle 50 of values when ordered from lowest to highest.
The lower quartile is the median of the lower half of the data.
The lowest value is numberd 13 the lower quartile is numberd 15 the median is numberd 21 the upper quartile is numberd 23 the highest value is numberd 27. The 3 types of quartiles are. Quartile 1 Q1 is the median of the lower half of the values. 2 nd quartile or middle quartile also same as median it divides numbers into 2 equal parts.