if x is 0 how to calculate x what is an example of a type variable when a dummy r variable is used, which r function is used? how to create a dummy variable with value x what is the reference level for a categorical variable how do you find the categorical variable x for linear regression how do we get the reference level of a linear regression? what is the reference level for the categorical variable $x? what type of data is the categorical variable $x what if x is the reference level for categorical variables how to calculate the reference level in regression analysis what is the reference level in java which dummy variable is used in the linear regression equation? how to get x-0 in a linear regression why use dummy variable x if a variable is a categorical variable, how much does it mean how to interpret data from categorical variables which variable is used for the reference level in a linear regression model? what is the reference value for $x what is the reference level for categorical variable $x?