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INPUT (x)
OUTPUT (y)
*Independent Variable/Quantity
*Dependent Variable/Quantity
The dependent variable depends upon the independent variable.
For example: Joe buys used CDs for $4 each. Therefore…
# of CDs Purchased
Total Cost
(x) – Indep.
(y) – Dep.
0
1
2
3
$0
$4
$8
$ 12
You can use the data from the chart to create ordered pairs, which can then be plotted
on a coordinate grid. (Input, Output) is the same as (x, y).
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This graph will contain the points (0, 0), (1, 4), (2, 8), (3, 12), etc.
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This is a multiplicative relationship (y = 4x), so it WILL intersect the origin.
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The independent variable is always labeled along the x-axis (horizontal), and the
dependent along the y-axis (vertical).