Stem and leaf diagrams
A stem and leaf diagram is a numerical representation of the data where the most significant digit is highlighted.
Example
Show the following data in a stem and leaf diagram.
\(36, 49, 37, 23, 54, 26, 29, 22, 37, 28, 20, 47, 56, 28, 59, 32\)
For these numbers the most significant digits are the ‘tens’ digits. These run from \(2\) to \(5\).
Initially the diagram is set up like the one above.
The unit digits are now included by taking each number in turn
\(36\) - we put a \(6\) in the \(3\) line.
\(49\) – we put a \(9\) in the \(4\) line.
\(37\) - we put a \(7\) in the \(3\) line.
Continue through all the numbers.
A number to the left of the line is called a stem.
A number to the right of the line is called a leaf.
Each stem can have any number of leaves.
Now arrange the leaves in numerical order and put in a ‘key’ to the diagram. The key compares how a number is shown in the diagram to how it would normally be written.
Question
A maths test is marked out of \(50\). The marks for the class are shown below:
\(7, 36, 41, 39, 27, 21\)
\(24, 17, 24, 31, 17, 13\)
\(31, 19, 8, 10, 14, 45\)
\(49, 50, 45, 32, 25, 17\)
\(46, 36, 23, 18, 12, 6\)
Show this data in a stem and leaf diagram.
Question
From the previous stem-and-leaf diagram, how many children scored more than \(40\)?
\(6\) people had a score of more than \(40\).
To find this, look down the stem to the row labelled \('4'\). Don't forget to include the child who scored \(50\).
