if I fit the regression analysis for a nominal variable (manipulated as two conditions) as IV, and a continuous variable as DV, at the same time, I add three covariates into the model. I wonder whether the covariates would be automatically mean-centred in the result table for this regression. for example, the "parameter estimates table" shows:
"intercept"
"nominal variable"
"covariate 1"
"covariate 2"
"covariate 3"
moreover, once I add an interaction effect between the nominal variable and another continuous variable. I awarded that the continuous variable is mean-centred. For example: the "parameter estimates table" table shows
"intercept"
"nominal variable"
"covariate 1"
"covariate 2"
"covariate 3"
"another continuous variable"
"nominal variable * another continuous variable (average- 3.13)"
I know 3.13 is the mean value of "another continuous variable", but I am not sure whether "covariate1", "covariate 2" "covariate 3" and "another continuous variable" are mean-centred or not in this multiple regression model.
