Bar Graphs

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)

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

Step One: Draw your axis:

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

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

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

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

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

{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

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

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

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?

What is a Bar Graph? Boys and Girls in each Science Class Period Boys Girls 2 10 8 5 8 10 6 11 7 7 8 12

Step One: Draw your axis:

Step Two: label your axis: 15 # of Boys/Girls 10 5 2 5 6 7 Science Classes

Step Three and Step Four: Plot your data and fill in your bars: 15 # of Boys/Girls 10 5 2 5 6 7 Science Classes: Boys Girls

Step Five: ???? TITLE: Boys and Girls in Each Science Class 15 # of Boys/Girls 10 5 2 5 6 7 Science Classes

Step Five: ???? {x vs. y} Science Class vs. the Number of Boys and Girls 15 # of Boys/Girls 10 5 2 5 6 7 Science Classes

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

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

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

Table of Plant Days vs. Plant Height: Make a Bar Graph: F-Plant 1 NF-Plant 2 (inches) (inches) 2 2 4 4 8 7 10 8 14 9 Day of Growth 2 5 10 15 20

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

What is wrong with this Graph (2 things) ? : 14 12 10 Height of Plant 8 6 4 2 2 5 10 15 20 Days of Growth F-Plant 1 NF- Plant 2

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

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

Knap-sack brand vs Students