Transcript Steps to making a line graph powerpoint.

7 Steps to making a
line graph
How to construct a line graph
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7 steps to making a line graph
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Identify the variables
Determine the range
Determine the scale
Number and label each axis
Plot the data points
Draw the Trend line
Title the graph
(1) Identify the variables
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Independent variable
Always found on the Left
of a Data Table
Goes on the X axis (MIX)
Dependent variable
•Always found on the right of a
data table
•Goes on the Y axis (DRY)
Sample Data table
Number of days
Number of bacterial
Colonies
0
0
1
6
2
12
3
36
4
120
5
240
6
400
7
600
(2) Determine the range
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What values must be on this
graph?
Subtract the lowest data value
from the highest data value.
(Each Variable)
This must be done for each
Variable
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Independent 7-0= 7
Seven numbers must fit evenly
across the bottom of the graph
Dependent 600-0=600
Six hundred numbers must fit
evenly up the side of the graph
Sample Data table
Number of days
Number of bacterial
Colonies
0
0
1
6
2
12
3
36
4
120
5
240
6
400
7
600
(3) Determine the scale
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The numerical value for each square.
What scale should be used so that all
your values fit on the graph?
The scale can be different for each
axis
Must fill at least 75% of the
graph paper
Try the basics
Count by 2,5,10, etc.
700
600
500
400
•The graph to the side has
seven blocks across its Y axis, 300
we need 600 numbers to fit,
200
therefore each block should
count as one hundred numbers.
100
•The graph to the side has
eight blocks across its X
0
axis, we need 7, therefore
0
each block should count as
one number
1
2
3
4
5
6
7
8
(4) Number and Label Both Axis
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After writing in the numbers on both axis write descriptive labels for each axis
Include
 Name of variables (From data Table)
 Measurement type from the Metric System
(Units, if included on Data table)
700
600
Number of Colonies
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500
400
300
200
100
0
0
1
2
3
4
Number of Days
5
6
7
8
(5) Plot the data points
Putting your data on the graph, from the
data table
Your first data point is (0,0)
Your second point is (1,6) count over 1
space and up to where the 6 would be.
Place a dot there.
Your third point is (2,12) Count over 2
and up 12 and place a dot there.
Continue though the data table
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700
Number of
days
Number of
bacterial
Colonies
0
0
1
6
2
12
3
36
4
120
5
240
100
6
400
0
7
600
Number of Colonies
600
500
400
300
200
0
1
2
3
4
Number of Days
5
6
7
8
(6) Draw the trend line
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DO NOT CONNECT THE DOTS!!
Draw a line which best fits the patterns you created (Best fit
line)
This does not have to HIT every DOT!!!
Can be a curve or a straight line, It shows the pattern!
700
600
Number of Colonies
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500
400
300
200
100
0
0
1
2
3
4
Number of Days
5
6
7
8
(7) Title the graph
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Use a descriptive title or the formula below
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Dependent VS. Independent
Number of Colonies V.S. Number of Days
This graph is
complete !!
700
Number of Colonies
600
500
400
300
200
100
0
0
1
2
3
4
Number of Days
5
6
7
8
7 steps to making a line graph







Identify the variables
Determine the range
Determine the scale
Number and label each axis
Plot the data points
Draw the trend line
Title the graph
Finding the correct spacing
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Divide the scale by the range.
If >1
 Round up to the nearest whole number, every line
will equal that value
If <1
 Divide the range by the scale, round down to the
nearest whole # and every line equals that value