Further Correlation & Regression (A Level only) (Edexcel A-Level Mathematics): Flashcards

Strength & direction of linear relationship between variables

$-1$ to $1$

Perfect positive linear correlation

Perfect negative linear correlation

No linear correlation

As $x$ increases, $y$ increases

As $x$ increases, $y$ decreases

Strong linear relationship

When relationship between variables is not linear

$y = ax^2 + bx + c$

$y = ab^x$

$y = a\ln(x) + b$