The graph shows a red arrow beginning at 4 (with a solid dot) and extending infinitely to the right, indicating all values greater than or equal to 4.

The interval in interval notation is: $[4, \infty)$

This means the interval includes 4 (since there is a solid dot), and extends to infinity, which is not included (indicated by the parenthesis).

Would you like more details on interval notation or have any questions?

Here are some related questions to deepen your understanding:

1. What does it mean when we use a bracket [ or parenthesis ( in interval notation?
2. How would the interval notation change if the dot at 4 was open (instead of solid)?
3. What is the meaning of negative infinity in interval notation?
4. How would you write the interval notation for values between -2 and 5, excluding 5?
5. Can an interval include infinity or negative infinity?

Tip: In interval notation, always use a parenthesis for infinity or negative infinity because they are not specific, fixed values that can be included.