List all the numbers in the stem-leaf diagram and find the middle number. Odd numbers are one, and the average of the middle two numbers in even numbers is the median. Average is to add up all the numbers and then divide by this number. The mode refers to the value of obvious concentration of trend points in the stem-leaf diagram, which is the value with the highest frequency in a group of data.

Extended data:

1) median is the representative value of all unit sign values determined by its position among all sign values, and it is not affected by the maximum or minimum value of distribution series, thus improving the representativeness of median to distribution series to some extent.

2) When the number distribution of some discrete variables is deviated, the representativeness of the median will be affected.

3) tend to be in the middle of an ordered set of data.

The function of stem-leaf diagram in quality management is similar to histogram, but it is usually used as a more detailed analysis stage. Because it is a histogram composed of numbers, when we compare histograms, we usually use professional software to draw them.

Baidu encyclopedia-stem leaf map