1. Bar Graphs

2. DEFINITION:
a BAR GRAPH is a diagram in which separate but related items are represented by rectangular shapes called “bars”
the horizontal axis usually represents the independent variable (manipulated variable)
the vertical axis usually represents the dependent variable (responding variable)

3. Absences today 5th grade 7 6th grade 12 7th grade 4
EXAMPLE:
Absences today
5th grade 7
6th grade 12
7th grade 4
Put this in a bar graph

4. Step One: Draw your axis:

5. Step Two: label your axis:15 10
# of Absences 5
5th 6th 7th
Grade Level

6. Step Three: plot your data:15 10
# of Absences 5
5th 6th 7th
Grade Level

7. Step Four: Fill in your bars:15 10
# of Absences 5
5th 6th 7th
Grade Level

8. Step Five: What is Missing?
TITLE YOUR GRAPH! 15 10
# of Absences 5
5th 6th 7th
Grade Level

9. Step Five: Possible Title --
Absences in Each Grade Level 15 10
# of Absences 5
5th 6th 7th
Grade Level

10. {x vs. y} Grade Level vs. Absences
Step Five: Alternative Title
{x vs. y} Grade Level vs. Absences 15 10
# of Absences 5
5th 6th 7th
Grade Level

11. Putting It All Together …
The intervals are the same spacing.
Title
Label y-axis
Label x-axis

12. Example:
What is the difference between boys and girls on Team A in each Science Class?
2nd period: 10B 8G
5th 8B 10G
6th 7G 11B
7th 12G 8B

13. What should we do first?
We should probably put our “raw data” into a better and simpler data table.
2nd period: 10B 8G
5th 8B 10G
6th 7G 11B
7th 12G 8B
any suggestions?

14. What is a Bar Graph? Boys and Girls in each Science Class
Period Boys Girls

15. Step One: Draw your axis:

16. Step Two: label your axis:15
# of Boys/Girls 10 5
Science Classes

17. Step Three and Step Four:
Plot your data and fill in your bars: 15
# of Boys/Girls 10 5
Science Classes:
Boys Girls

18. Step Five: ????
TITLE: Boys and Girls in Each Science Class 15
# of Boys/Girls 10 5
Science Classes

19. Step Five: ???? {x vs. y}
Science Class vs. the Number of Boys and Girls 15
# of Boys/Girls 10 5
Science Classes

21. Tips for Bar Graphs?
The independent variable always goes on the x axis. (What does that mean?)
Title and Label all axis. Include the units!
Determine the correct “scale” to be used on the graph.
Make sure your vertical axis uses a scale which is consistent and does not change

22. The width of all bars should be the same
Tips for Bar Graphs?
The width of all bars should be the same
You should leave a “skipped” space between each separate bar group.
That “skipped” space should be the same distance for each category

23. Tips for Bar Graphs?
TITLE YOUR GRAPH
Don't forget!

24. Table of Plant Days vs. Plant Height: Make a Bar Graph:
F-Plant NF-Plant 2
(inches) (inches)
2 2
4 4
8 7
10 8
14 9
Day of Growth 2 5 10 15 20

25. Height of Plant Days of Growth : 14 12 10 8 6 4 2 2 5 10 15 20
Days of Growth
F-Plant 1 NF- Plant 2

26. What is wrong with this Graph (2 things) ?: 14 12 10
Height of Plant 8 6 4 2
Days of Growth
F-Plant 1 NF- Plant 2

27. Days of Growth vs. Plant Height: 14 12 10
Height of Plant 8 6 4 2
inches
Days of Growth
F-Plant 1 NF- Plant 2

28. Knap-Sack Brand
Brand
Number of Boys
NIKE 20
FUBU 40
Polo 30
TARGET 10

29. Knap-sack brand vs Students