Formulae for Correlation and Regression (HSC SSCE Mathematics Advanced): Flashcards

Linear correlation between variables

$r$ is a pure number with no units

$\frac{\sum (x-\bar{x})(y-\bar{y})}{\sqrt{\sum(x-\bar{x})^2\sum(y-\bar{y})^2}}$

$m = \frac{\sum (x - \bar{x})(y - \bar{y})}{\sum (x - \bar{x})^2}$

$b = \bar{y} - m\bar{x}$

$(\bar{x}, \bar{y})$ - the mean point

$0.6$ to $1.0$

$0.4$ to $0.6$

$0.1$ to $0.4$

They are the same: $\sum (x - \bar{x})(y - \bar{y})$