Create an  AVL Tree for the given values 21, 26, 30, 9, 4, 14, 28, 18,15,10, 2, 3, 7.  What is the root node element.*1 point1041415

To create an AVL Tree for the given values, we will follow these steps:

1. Start with an empty AVL Tree.
2. Insert the first value, 21, as the root node.
3. Insert the next value, 26, as the right child of the root node.
4. Insert the next value, 30, as the right child of the node with value 26.
5. Insert the next value, 9, as the left child of the root node.
6. Insert the next value, 4, as the left child of the node with value 9.
7. Insert the next value, 14, as the right child of the node with value 4.
8. Insert the next value, 28, as the right child of the node with value 26.
9. Insert the next value, 18, as the left child of the node with value 14.
10. Insert the next value, 15, as the left child of the node with value 18.
11. Insert the next value, 10, as the left child of the node with value 9.
12. Insert the next value, 2, as the left child of the node with value 4.
13. Insert the next value, 3, as the right child of the node with value 2.
14. Insert the last value, 7, as the right child of the node with value 4.

After following these steps, the AVL Tree will be constructed. The root node element of this AVL Tree is 21.