Graphing
Did you have a growth chart as a baby?
This graph tells us how much weight (in Kilograms) a baby gained in 36 months.
This graph shows us the increase and the number of people
using Facebook from March 2004 to March 2007
Number of People
This graph shows us the number of people who have a certain
type of pet.
Types of Pets
What does this graph show us?
A graph can be used to make comparisons
What conclusion can you make?
This pie chart shows how much time Teensy spent writing her
English essay.
Rules for constructing a graph
1. Always provide
a title for your graph
Without a title the data has no meaning
Always label the X and Y axis
Y
X
The independent variable is what the investigator deliberately varies
during the experiment. It is chosen because the investigator thinks it
will affect the dependent variable. This is represented on the X axis.
The dependent variable is what the investigator measures (or
counts or records). It is what the investigator thinks will vary
during the experiment. For example, he may want to study
peanut growth.
One possible dependent variable is the height of the peanut
plants. This is represented on the Y axis.
What Type of Graph?
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Bar Graph – comparing groups
Line Graph – change over time
Pie/Circle Graph- parts of a whole
Scatter Plot – correlation of variables
Histogram – distribution of data
• Video
Do Now 8/31-9/1
What are the independent
and dependent variables in
these two experiments?
Are either of these graphs
missing information?
What?