baseline and the third approach is the removal of the outliers so how can you do the removal you just build a model and predict on the train dataset and you have to use a cross validation approach it's mandatory otherwise it's not going to work and you will predict and using those prediction you will get an error and based on this error you will find an optimal threshold and you will remove from your training data all the samples that have an error higher than the threshold that you have fixed during the testing you should not apply the