The following stem-and-leaf plot represents the scores earned by mr. roberts's class on their most recent science test.

what is the median of the scores?
78
80
81
86

The median of {78, 80, 81, 86} is the average of the middle two scores, 80.5.


For the picture, ...

There are 7 scores above the row with stem=8, and 7 scores below that row. Thus the middle score will be the middle score of the row with stem 8.

The median of the scores in the figure is 81.