Elements of a Graph
Insanity of Statements
Why use a graph?Graphs are very useful tools in science:
A graph is used by scientist to organize the facts so they can be analyzed and conclusions can be drawn.
Graphs are pictorial representation of recorded information.
Used to show the relationship between 2 or more different factors.
Graphs make trends in data easy to see.Graphs allow us to predict data that is not measured.
There are several different types of graphs:BAR GRAPH
CIRCLE/PIE GRAPH
LINE GRAPH
Bar GraphUsed to compare data for several
individual items or events.Number of pets in Mrs. O’Neill’s block 3 class.
Circle or Pie Graph:Used to display data that are parts
of a whole.Can be compared by percentages or by the size of the “sections/parts”.
The different types of pies that the students in Mrs. O’Neill’s block 3 class enjoy eating.
Line GraphsUsed to show something that is being measured as it changes over a period of time.
Can be used to predict what will most likely happen next.
Line graphs allow us to predict data that is not measured:
Extrapolate: extend graph along the same
slope, above or below the measured data.
Interpolate: predicting data between two
measured points on a graph.
Rules for making a line graph:
#1 Assign and label your X and Y axes:X axis:
Located on the bottom of the graph /horizontal axis
Shows the most consistent or independent variable
The independent variable occurs no matter if the experiment is occurring or not. It is most often time.
Independent variable is controlled by the person conducting the experiment.
X
Y
Y axis:Located on the side of the graph /vertical axis
Shows the variable which is dependent on the other variable.
The dependent variable is the one that depends on what happens in the experiment
X
Y
Example:
Independent variable:
- time in years
Dependent variable:
-population size
#2 Make a scale for each axes based upon the data collected.
#3 Utilize as much of the graph paper as possible.
#4 Plot the data points.
#5 Connect the data points with a straight
edge.
#6 Give the graph a meaningful title.
#7 Provide a key if graphing more than one
set of data points on the same graph.
Graphing PracticeHow far does a soap box car travel after 10
seconds?Time (seconds)
Distance (meters)
0 0
1 2
2 8
3 18
4 32
5 50
6 72
7 98
8 128
9 162
10 200
Q & AWhat is the rate of photosynthesis at 10C?
50
What is the dependent variable in the graph? Rate of photosynthesis
At what temperature is the rate of photosynthesis at its highest?
30 degrees