what is standardisation of the explanatory variable which variables are standardised why do we standardise the variable $y$ when scaled data is standardised why are variables scaled which variable is scaled to zero mean why is data scaled what is standardising data why don't we scale the data of the explanatory variable $x$? what scale should a variable be why do the explanatory variables scale to a zero mean why is a model scaled how to standardize data scales how to scale data which is an example of using scalancing why should a data scale be scaled what is r scale what is standardised data scales of variable why does r scale data which data type has the highest mean of all variables