Answer:
fourth option
Step-by-step explanation:
The mean is calculated as
mean = 
= 
= 
= 23.6 ( to 1 dec. place )
The median is the middle value of the data set. If there is no exact middle then it is the average of the values either side of the middle.
15 16 21 23 25 25 25 39
↑ middle
median =
=
= 24
The mode is the value that occurs most often, that is 25
Thus
mean = 23.6 , median = 24 , mode = 25