Scatter Plot Vocabulary

Scatter Plots!
What’s a Scatter Plot?
Two sets of data are plotted as ordered pairs in the coordinate plane
and show the relationship/correlation between two variables.
• The points in a scatter plot often show a pattern,
TREND
or ____________.
• From the pattern or trend you can describe the
CORRELATION
________________.
Variables
X
The independent variable is located on the ___________ axis.
This variable does not depend on the other variable.
Y
The dependent variable is located on the ____________ axis.
This variable depends on the other variable.
Input (time)
Independent variable: _______________
Output (Money)
Dependent variable: _____________
Note:
The independent variable
comes first in the table of
values.
Correlation: the relationship between the
dependent and independent variables
For our purposes and with our data…
relationship, trend, and correlation are synonyms.
Correlation/Relationship/Trend
Positive Correlation:
As x increases,
y increases
Negative Correlation: As x increases,
y decreases
No Correlation: The variables are not related
so they are independent.
Correlation/Relationship/Trend
Linear Correlation:
Looks like a line (there is a constant ratio), can be
positive or negative
Non-linear Correlation: Data points have a curved pattern/trend
Strong Correlation: The data points are close to each other and have a
clear pattern/trend.
Weak Correlation: The data points are farther apart but still have a
pattern/trend.
Examples:
Describe the correlations in each scatter plot below:
--Which variable is the independent variable?
--Does Julie’s age depend on how tall she is?
--Or does her height depend on how old she is?
Example:
Julie gathered information about her age and height from the markings on the
wall in her house.
Age (years)
1
2
3
4
5
6
7
8
Height (cm)
70
82
93
98
106
118
127
135
a) Label the vertical axis.
b) Describe the trend in the data.
c) In a complete sentence, describe the relationship between Julie’s age and her height.