Linear Correlations

If every brother is exactly two inches taller than his sister, what would the correlation between the heights of brothers and sisters be?

• Nearly 1

• 0

• Somewhat positive

• 1

r is only useful for ...

• Quadratic functions

• Linear functions

r = -0.3 is considered to have...

• moderate negative correlation

• weak negative correlation

• no correlation

• strong negative correlation

What type of relationship does this graph have?

• Positive Association

• Negative Association

• No Association

Estimate the correlation coefficient for this scatterplot.

• r = -0.9

• r = 1

• r = 0.9

• r = -1

Estimate the correlation coefficient for this scatterplot.

• r = 1.2

• r = 0.89

• r = 0

• r = -0.89

Which scatterplot suggests a linear association?

• 
• 
• 
• 

The following scatter plot shows the weights and lengths of some dinosaurs.  Which statement accurately describes the information?

• The information shows a positive correlation.  The weight of a dinosaur tends to increase according to its length.

• The information shows a negative correlation.  the weight of a dinosaur tends to decrease according to its length.

• The information shows no correlation.  The weight and length vary according to the type of dinosaur.

• The information shows no correlation.  The relationship between the weight and length of a dinosaur is uncertain.

What type of correlation do the data here represent?

• positive

• negative

• no correlation

Describe the strength and direction of the trend

• Moderate Negative Trend

• Strong Negative Trend

• Moderate Positive Trend

• Strong Positive Trend