Suppose that the data mining task is to cluster points (with (x, y) representing location) into three clusters, where the points are a1(2,10),a2(2,5),a3(8,4),b1(5,8),b2 (7,5),b3(6,4),c1(1,2),c2(4,9). the distance function is euclidean distance. suppose initially we assign a1, b1, and c1 as the center of each cluster, respectively. use the k-means algorithm to show only (a) the three cluster centers after the first round of execution. (b) the final three clusters.

The great length of north america causes the climate to be varied. true false

Suppose there is a relation r(a, b, c) with a b+-tree index with search keys (a, b).1. what is the worst-case cost of finding records satisfying 10 < a < 50 using this index, in terms of the number of records n1, retrieved and the height h of the tree? 2. what is the worst-case cost of finding records satisfying 10 < a < 50 and 5 < b < 10 using this index, in terms of the number of records n2 that satisfy this selection, as well as n1 and h defined above? 3. under what conditions on n1 and n2, would the index be an efficient way of finding records satisfying the condition from part (2)?

Acompany is hiring professionals for web designing. the firm is small with few resources. they want employees who possess problem-solving skills and can independently carry out responsibilities. which kind of employee should they select?