Scatter Plots!

What’s a Scatter ? Two sets of 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, or ______TREND___. • From the pattern or trend you can describe the ______CORRELATION . Variables The independent is located on the ______X axis. This variable does not depend on the other variable.

The dependent variable is located on the ______Y axis. This variable depends on the other variable.

Independent variable: ______Input (time)

Dependent variable: ______Output (Money)

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 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.