Scatterplots, Trend Lines, Associations

Choose the scatter plot that best represents this relationship: The number of pets someone owns and the size of their shoes

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What is a scatter plot?

• A graph that shows the relationship of two data sets.

• A graph drawn using rectangular bars to show how large each value is.

• A graph that shows information that is connected in some way.

• A graph that shows data changing over time.

Which scatter plot shows a linear relationship between x and y?

• Graph A

• Graph B

• Graph C

• Graph D

Estimate the correlation coefficient

• r = 1

• r = -1

• r ≈ -0.8

• r ≈ 0.8

• r ≈ -0.5

Which best describes the form of this scatterplot?

• linear

• nonlinear

• scattered

What is the equation of the line of best fit?

• y = -25x + 170

• y = -5/8x + 170

• y = 25x + 170

• y = 5/8x + 170

The equation of the trend line is y= 1/2x +1

How many laps can a bicycle make around the park in 11 minutes?

• 44 laps

• 12 1/2 laps

• 20

• 23

A researcher gathered data to predict the number of new types of plants (y) that will be in a state park after x years.  After making a scatter plot of the data, she determined the equation of a line of best fit to be
y = 0.25x + 8
Based on the equation, what is the number of new types of plants that will be in the park after 24 years?

• 8

• 14

• 32

• 64

Describe the correlation coefficient if

r = 0.90

• Positive, weak

• Positive, strong

• Negative, weak

• Negative, strong

Describe the correlation:

r = -0.98

• Strong positive

• Weak positive

• Strong negative

• Weak negative