Stem and Leaf Display

 

It is the valuable tool for organizing the set of data and understanding the distribution of data in the data set. It separates the whole data into two parts: leading part and trailing part. A single data is used to define each leaf and if leaf is not shown, it is assumed to be one.

A good stem and leaf plot :

• shows the first digits of the number (thousands, hundreds or tens) as the stem and shows the last digit (ones) as the leaf.
• usually uses whole numbers. Anything that has a decimal point is rounded to the nearest whole number. For example, test results, speeds, heights, weights, etc.
• looks like a bar graph when it is turned on its side.
• shows how the data are spread—that is, highest number, lowest number, most common number and outliers (a number that lies outside the main group of numbers).

 

For Example:

56, 78, 82, 82, 90, 94, 93, 67, 67, 69, 74, 77, 92, 88, 81, 83, 84, 77, 72

Arranging the data in the ascending order:

56, 67, 67, 72, 74, 77, 77, 78, 81, 82, 82, 83, 84, 88, 90, 92, 93, 94