Suppose you have a dataset that contains 1989 documents in total. These documents fall into 4 categories: financial, foreign, metro and national, which serve as true labels. Suppose you run a clustering method on this dataset to obtain 4 clusters. The confusion matrix resulted from the clustering analysis is in below. Cluster 1 2 3 4 Total Financial 5 7 162 358 532 Foreign 40 280 3 12 335 Metro 506 29 119 212 866 National 96 39 73 48 256 Based on this confusion matrix, please compute the entropy and purity of Cluster 3 (please do not just write down the numbers, show how you compute them).