1. Assume you have an index key with the following values 5, 10, 15, 20, 25, 50, 55, 25, 30, 50, 75, 75, 60, 65, 80, 85, 90. Create a B+ tree index; consider each node is 4 keys. 2. Insert the key 28 to the tree above. (redraw the resulting tree) 3. Insert 70 to the tree above.. (redraw the resulting tree)