Answer: The median of the dataset is 4.
Step-by-step explanation: There are 15 samples in total. The median is the middle element of a list of these samples ordered by value (say, in an ascending order). The histogram shown gives us the ordering information, so we can simply read the middle element, i.e., the 8th element, off the dot plot:
2,2,2,3,4,4,4, >>4<<, 6, 6, 7, 7, 7, 8, 9
The median of the dataset is 4.