Coding (Edexcel A-Level Mathematics): Flashcards

A technique to simplify calculations by transforming data using a linear function

$y = \frac{x - a}{b}$

Coded value

Original data value

Constant used to shift the data

Constant used to scale the data

$\bar{y} = \frac{\bar{x} - a}{b}$

$\bar{x} = b\bar{y} + a$

$\text{Var}(y) = \frac{\text{Var}(x)}{b^2}$

$\text{Var}(x) = b^2 \times \text{Var}(y)$

$\text{SD}(y) = \frac{\text{SD}(x)}{b}$

$\text{SD}(x) = b \times \text{SD}(y)$