When the 12 numbers are listed in order, they are ...
... 13, 15, 18, 20, 23, 23, 27, 29, 30, 32, 36, 38
The extreme values are 13 and 38. Only the third plot has the ends of the whiskers on these values.
Since there are an even number of numbers, the median is the average of the middle two: (23 +27)/2 = 25. Only the third plot shows the median at 25.
Since each half of the data set has an even number of numbers, the 1st and 3rd quartile values are the averages of the middle two numbers in each half:
- 1st quartile — (18+20)/2 = 19
- 3rd quartile — (30+32)/2 = 31
The third plot has the ends of the box in these places, confirming it is the correct choice.
The appropriate choice is the third one.