Let us define the dataset we are going to employ for our modeling activity. We will employ clean_casted_stored_data_validated_complete, removing the default_flag and the customer_code first because it is actually meaningless as an explanatory variable:
clean_casted_stored_data_validated_complete %>% (-default_flag) %>% (-customer_code) -> training_data
And we are ready now to fit our model:
multiple_regression <- lm(as.numeric(default_numeric)~., data= training_data)
You should have already noticed the small point after the ~ token. It actually means that all the available explanatory variables will be fitted against the as.numeric(default_numeric) response variable. Before looking at model assumptions validation, we could go ...