Interpret stem-and-leaf plots
Key Notes :
What is a Stem-and-Leaf Plot?
- A stem-and-leaf plot is a way of organizing data to show the frequency of values in a dataset.
- It separates each data point into a “stem” (the leading digit) and a “leaf” (the trailing digit).
Structure of Stem-and-Leaf Plots:
- The stem represents the tens place (for example, in 34, the stem is 3).
- The leaf represents the ones place (for example, in 34, the leaf is 4).
- Data points are listed in order, with the smallest value at the top.
Reading a Stem-and-Leaf Plot:
- Look at the stem values first. The leaf values show the individual data points for each stem.
- For example, if the stem is 3 and the leaves are 1, 4, and 7, the values represented are 31, 34, and 37.
Interpreting the Data:
- You can easily see the distribution of data.
- Identify the smallest, largest, and middle (median) values.
- Determine the frequency of each value or range of values.
Benefits of Stem-and-Leaf Plots:
- They allow you to see the shape and distribution of data clearly.
- They are useful for comparing two sets of data when placed side by side.
Learn with an example
🛑 A shipping company keeps track of the number of boxes in each shipment they send out.
What is the largest number of boxes?
_______ boxes
Look at the last row of the stem-and-leaf plot. The last row has the highest stem. The stem for the last row is 9.
Now find the highest leaf in the last row. The highest leaf is 0.
The largest number of boxes has a stem of 9 and a leaf of 0. Write the stem first, then the leaf: 90.
The largest number of boxes is 90 boxes.
🛑 Ms. Herman reported her students’ scores on the most recent quiz.
How many students scored at least 20 points?
______ students
Count all the leaves in the rows with stems 2, 3, 4, 5, 6, and 7.
You counted 8 leaves, which are blue in the stem-and-leaf plot above. 8 students scored at least 20 points.
🛑 A crayon factory monitored the number of broken crayons per box during the past day.
What is the smallest number of broken crayons?
_______ broken crayons
Look at the first row of the stem-and-leaf plot. The first row has the lowest stem. The stem for the first row is 0.
Now find the lowest leaf in the first row. The lowest leaf is 5.
The smallest number of broken crayons has a stem of 0 and a leaf of 5. Write the stem first, then the leaf: 05.
The smallest number of broken crayons is 5 broken crayons.
Let’s practice!🖊️
