Style chart is a method to represent data in statistics. The stem usually refers to the number in the middle column, and the leaves are the numbers growing from the side of the stem. The middle number represents the ten digits (or hundredths) of the score, and the following numbers represent the single digits (or tens) of the score.

The characteristics of stem-leaf diagram: it can not only retain the original data, but also display the distribution of the data.

The peak value refers to the most prominent row (or several adjacent rows with the same length) in the leaf distribution.

If there is only one most prominent one on the stem-leaf diagram, it is called unimodal. If there are two or more prominent figures in the stem-leaf diagram, it is called multimodal.

Case study:

In this diagram, both A and B are unimodal. A has three adjacent rows with the same length, so it is unimodal, but the data are mainly concentrated on the stems of 1, 2,3. B is also unimodal, and the data are mainly concentrated in the stem of 3. So b is more stable.