12.12 Coding data

AQA Edexcel OCR A OCR B (MEI)
Coding is a way of simplifying data. Each value is converted using a formula to produce a new set of values which are easier to work with.

If the data are coded using the formula y=xaby = \dfrac{x-a}{b},

then the mean is given by yˉ=xˉab\bar{y} = \dfrac{\bar{x}-a}{b},

and the standard deviation is given by σy=σxb\sigma_y = \dfrac{\sigma_x}{b}.
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