42
Explanation:
Step 1 :
Given data set - 14,18,20,21,25,32,40,44,48
We need to get the 3rd quartile
Step 2 :
To find the quartile's , we have to divide the data set into 4 equal quarters.
The 3rd cut will give the 3rd quartile
Step 3:
The median of this data set is at 25, there are 4 numbers below and above it.
Now we take the 2nd half of the set , after the median and take the median of it.
There are 4 numbers in the 2nd half 32,40,44,48. Cutting this into 2 , we have the cut to fall between 40 and 44. Hence taking the average of this will give the 3rd quartile.
The average of 40 and 44 is 42 .
Hence the 3rd quartile is 42.