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.

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.

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.

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.

Front

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

Back

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

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.

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.

Front

What is the range of correlation coefficients?

Back

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

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.

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.