1. Stem and Leaf Plots

2. Definitions- Range
Range- The difference between the greatest and least numbers in a data set
Data set: 23, 45, 60, 55, 80, 75, 15
Largest number: 80
Smallest number: 15
Difference: 80-15= 65
The Range

3. More on Range Range is not a measure of central tendency.
It is a measure of variation…..it describes the spread of the data.

4. Stem and Leaf Plots What is a stem and leaf plot?
It is a way to represent specific data.
It organizes data so it can be analyzed visually and mathematically
When is it appropriate to use a stem and leaf plot?
When data can be grouped into intervals (stems) and the data values within the intervals can be plotted as the leaves.

5. Parts of stem and leaf plots
This is the leaf
This is the stem

6. 56 Leaf Stem Stem and Leaf Plots
In a Stem and Leaf Plot, the data are organized from least to greatest. The digits of the greatest place value usually form the Stems, the next place value of digits form the leaves. 56
Leaf
Stem

7. Stem and Leaf Plots How do we create them? We start with a data set
All data should be in order from least to greatest.
Each stem and each leaf must be represented.
Always list the digit even if it is repeated

8. Data set
Chick Weight (grams) 19 6 7 10 11 13 18 25 21 12 5 20
Use the following data set to create a stem and leaf plot

9. Stem and Leaf Plots
Step 1: Create the graph
Stem
Leaf

10. Stem and Leaf Plots
Step 2: Choose the stems using digits in the tens place 19 6 7 10 11 13 18 25 21 12 5 20
What are the stems? (digits in the tens place)
0, 1, 2
The least value is 5, it has a 0 in the tens place
The greatest value is 25, it has a 2 in the tens place

11. Stem Leaf 0 12 Stem and Leaf Plots
Step 3: List the stems in order from least to greatest.
Stems: 0, 1, 2
Stem
Leaf

12. Stem Leaf Stem and Leaf Plots
Step 4: Order the leaves – least to greatest 19 6 7 10 11 13 18 25 21 12 5 20
Stem
Leaf 1 2
5 6 7
The tens digits form
the stems
Always write each leaf even if the data repeats
Always add a
Key: 1|2 = 12 g
The ones digit
Forms the leaves

13. Add a title!!!! Completing Graph
What do we always do before completing a graph?????????????
Add a title!!!!

14. Making Inferences
When you analyze data, you can make inferences. That means, we can draw conclusions based on the data.

15. 10 25 12 Making Inferences Find the mode ______ Find the range ______
Find the median _____
Miles Jessie biked 25
Stem
Leaf 12 1 2 3
5 5 6
The stem and leaf plot shows the number of miles Jessie biked each day during the month of July.
2|1 = 21 miles

16. 5 30 4 Analyzing Data 2|1 = 21 miles
What was the least number of miles Jessie biked in July? _______
What was the largest number of miles Jessie biked in July? _______
How many days did Jessie bike only 10 miles? ____
Miles Jessie biked
Stem
Leaf 5 1 2 3
5 5 6 30 4
2|1 = 21 miles

17. Making a stem and leaf plot
Make your own graph
Making a stem and leaf plot
Use the data in the following table to create your own stem and leaf plot.
Quiz scores in Coach Bowen’s Class 70 96 72 91 80 79 93 76 95 73 90 77

18. Does it look like this? Quiz scores in Coach Bowen’s Class Stem Leaf 78 9
0 0
9|1= 91 on quiz

19. Answer the questions about your graph
What is the highest score on quiz? ____
What was the lowest score on quiz?____
What is the mode? ____
What is the median ____
What is the range of the quiz scores? ___ 96 70 93 85 26

20. Question
Can we use stem and leaf plots to represent all data? No

21. Conclusion: Stem and Leaf Plots
Are easy to read
Are easy to create
Great graph to display data
Can not be used for all data sets