Here is the updated binary search tree after inserting the value 4. If you have any further questions or need explanations, let me know!

Would you like further details on the insertion process or the properties of a binary search tree?

Here are some related questions for further exploration:

1. What is the height of the updated tree?
2. How do you verify if a tree is a valid binary search tree?
3. What is the in-order traversal of the updated tree?
4. Can you explain how the insertion affects the balance of the tree?
5. How would the tree change if we inserted 7 instead of 4?

Tip: In-order traversal of a binary search tree always produces a sorted sequence of values!