Linear Correlation and Correlation Coefficient

Front

What is a positive correlation?

Back

A positive correlation occurs when two variables move in the same direction; as one variable increases, the other also increases.

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CCSS.HSS.ID.B.5

Front

What is a negative correlation?

Back

A negative correlation occurs when two variables move in opposite directions; as one variable increases, the other decreases.

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CCSS.HSS.ID.B.5

Front

What does a correlation coefficient (r) of 1 indicate?

Back

A correlation coefficient (r) of 1 indicates a perfect positive correlation between two variables.

Tags

CCSS.HSS.ID.B.5

Front

What does a correlation coefficient (r) of -1 indicate?

Back

A correlation coefficient (r) of -1 indicates a perfect negative correlation between two variables.

Tags

CCSS.HSS.ID.B.5

Front

What does a correlation coefficient (r) of 0 indicate?

Back

A correlation coefficient (r) of 0 indicates no correlation between two variables.

Tags

CCSS.HSS.ID.B.5

Front

How can you visually identify a positive correlation on a graph?

Back

A positive correlation on a graph is identified by an upward slope, where points trend from the lower left to the upper right.

Tags

CCSS.HSS.ID.B.5

Front

How can you visually identify a negative correlation on a graph?

Back

A negative correlation on a graph is identified by a downward slope, where points trend from the upper left to the lower right.

Tags

CCSS.HSS.ID.B.5

Front

What is the range of correlation coefficients?

Back

The range of correlation coefficients is from -1 to 1.

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CCSS.HSS.ID.B.5

Front

What does a correlation coefficient close to 0 imply?

Back

A correlation coefficient close to 0 implies a weak or no linear relationship between the two variables.

Tags

CCSS.HSS.ID.B.5

Front

What is the formula for calculating the correlation coefficient (r)?

Back

The formula for calculating the correlation coefficient (r) is r = (nΣxy - ΣxΣy) / √[(nΣx² - (Σx)²)(nΣy² - (Σy)²)], where n is the number of pairs.

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CCSS.HSS.ID.C.8