Answer: 20
Explanation:
First, we put the data values in order from least to greatest.
10 13 14 19 20 23 31 33 39
Next, we will find the middle value of this list.
10 13 14 19 20 23 31 33 39
--- 13 14 19 20 23 31 33 ---
--- --- 14 19 20 23 31 --- ---
--- --- --- 19 20 23 --- --- ---
--- --- --- --- 20 --- --- --- ---
The median is 20.