(1) Consider the clustering C {C, C2, C3} with C = {x1, 2, 3, x4}, C = {x5, 26, 27, 28}, C3 = {x9, 10} and x; x; for i j. Compute the silhouette coefficient of the clustering with distance function given by - dist(xi, xj) = { 1 xi#xj Xi = X j (2) The silhouette coefficient depends on the number k of clusters. In the setting given above: What is the smallest silhouette coefficient over all clusterings with at least 2 clusters? When is that value attained?