Answer:
83
Step-by-step explanation:
An outliner is any data which is at abnormal distance from other data in a set of data. An outliner is generally excluded from data as this data brings error in the observation.
In the given set of data
21, 23, 19, 25, 83, 23, 21
all the numbers are near to 23
21, 19, 25
but 83 is much much away from 23 and hence 83 is outliner.
