Suppose that we have 5 observations, for which we compute a distance matrix, given by A B C D E A B С D 0.3 0.3 0.4 0.5 0.7 0.2 0.3 0.4 0.7 0.61 0.5 0.2 0.3 0.6 0.7 0.6 0.3 0.7 0.3 E L0.6 For instance, the distance between A and B is 0.3, and the distance between B and D is 0.2. a. Sketch the dendrogram that results from hierarchically clustering these five observations using average linkage. b. Suppose we want to group these four observations into 2 clusters. Which observations are in each cluster?