Stem and Leaf Plot

A stem-and-leaf plot looks something like a bar chart. Each number in the data is broken down int a stem and a leaf. The stem of the number includes all, but the last digit. The leaf of the number will always be one digit. Look at the stem and leaf table below that was built from the following data:

40, 42, 45, 49, 51, 54, 57, 58, 60, 63, 66, 66

 Stem Leaves 4 0 2 5 9 5 1 4 7 8 6 0 3 6 6

Key: 5 | 7 = 57

 Stem Leaves 2 0123456788

 Stem Leaves 12 0123456788

These diagrams should help you picture the meaning of stem and leaf. The first part of the number is the stem and the last digit is the leaf.

# Stem and Leaf Plot

To use this calculator, type or paste your data in the text window. As you enter them, separate the different values by
• spaces:     12 23 33 38 45
• commas:  12,23,33,38,45
• newlines
12
23
33
38
45
*copying and pasting HTML data separated by new lines requires editing!!

Hit the "Compute" button when you have finished entering your data.

Your browser will open a new window and display the Stem-and-Leaf plot. When you are done looking at the new window press the "Exit" button.

JavaScript source:  Stem and Leaf Plot

This chart shows different numbers and inicates the stem and leaf for each number.

 Number Stem Leaf 12 1 2 13 1 3 120 12 0 131 13 1 1252 125 2

Key: 125 | 2 = 1252

Let's examine a stem and leaf plot:
 stem leaf 10 5 11 023 12 055 13 025

The range of the 10 numbers shown is 105 to 135. The 10 numbers displayed above are:

105

110, 112, 113

120, 125, 125

130, 132, 135

The mean is the sum of the 10 numbers divide by 10.

mean = (105+110+112+113+120+125+125+130+132+135)/10

=1207/10 = 120.7

The median is the middle number of the 10 numbers in order. Since there are 10 numbers we will have to find the average of the 5th and 6th numbers.

median = (120 + 125)/2

=122.5

The mode is the number that occurs most often in a set of numbers. 125 is the only number that appears more than once.

mode = 125

A natural way to organize data is to arrange the data from least to greatest. For example, the 30 weights:

185, 160, 235, 165, 125, 175, 185, 132, 168, 112, 170, 155, 105, 158, 120, 190, 140, 185, 125, 180, 145, 110, 155 135, 170, 113, 155, 175, 145, 130

are more easily comprehended in order:

105, 110, 112, 113, 120, 125, 125, 130, 132, 135, 140, 145, 145, 155, 155, 155, 158, 160, 165, 168, 170, 170, 175, 175, 180, 185, 185, 185, 190, 235.

Note that each weight has been listed as many times as it occurs. This information can be visually presented with a stem and leaf plot. Remember that the leaf will always be one digit. The stems are listed on the left, and the corresponding leaves (if any) on the right. A stem and leaf plot for the above data is presented below.

 stem leaf 10 5 11 023 12 055 13 025 14 055 15 5558 16 058 17 0055 18 0555 19 0 20 21 22 23 5

range: 105 to 235

mean: 4598/30 = 153.2

median: (155+155)/2 = 155 (average of 15th and 16th numbers in set)

modes: 155, 185

Sometimes to enhance visual presentation of data, stems will be split (e.g., repeat each stem on the left, once for the digits 0-4, once for the digits 5-9).