Scatterplots, Trend Lines, Correlation

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, if the correlation coefficient is r = -0.26

• Positive, weak

• Negative, weak

• Positive, strong

• Negative, strong

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

Estimate the correlation coefficient.

• r is close to zero

• r is close to -1

• r is close to 1

• r is close to -1.5

• r is close to 1.5

What is the type of correlation?

• Negative 

• no correlation

• positive 

Make a prediction for a resting heart rate after 6 hours of exercise a week.

• 6

• 50

• 55

• 80

Describe the correlation. r = 0.3

• Strong, positive

• Weak, positive

• Strong, negative

• Weak, negative

What type of association does this graph have?

• positive

• negative

• none

• all of the above