Checking model results

In the previous exercise you've flagged all observations to be fraud, if they are in the top 5th percentile in distance from the cluster centroid. I.e. these are the very outliers of the three clusters. For this exercise you have the scaled data and labels already split into training and test set, so y_test is available. The predictions from the previous exercise, km_y_pred, are also available. Let's create some performance metrics and see how well you did.