7 Steps to making a line graph

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7 Steps to making a line graph

• How to construct a line graph
• Click the left mouse Button to advance the notes

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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

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(1) Identify the variables

• 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
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(2) Determine the range

• 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
• Independent 7-0 7
• Seven numbers must fit evenly across the bottom
  of the graph
• Dependent 600-0600
• 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
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(3) Determine the scale

• 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 basicsCount by 2,5,10, etc.

• The graph to the side has seven blocks across its
  Y axis, we need 600 numbers to fit, therefore
  each block should count as one hundred numbers.

• The graph to the side has eight blocks across its
  X axis, we need 7, therefore each block should
  count as one number

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(4) Number and Label Both Axis

• 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)

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(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

Number of days Number of bacterial Colonies
0 0
1 6
2 12
3 36
4 120
5 240
6 400
7 600
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(6) Draw the trend line

• 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!

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(7) Title the graph

• Use a descriptive title or the formula below
• Dependent VS. Independent

Number of Colonies V.S. Number of Days
This graph is complete !!
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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

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Finding the correct spacing

• Divide the scale by the range.
• If gt1
• Round up to the nearest whole number, every line
  will equal that value
• If lt1
• Divide the range by the scale, round down to the
  nearest whole and every line equals that value