By definition, there are the following intervals in Interval notation:
1. A Closed interval: It includes its endpoints. To write it, you must use brackets []
2. An Open interval: It does not include its endpoints, to write it you must use parentheses ().
For this case, since you need to find the set of all numbers from 5 to 12, inclusive, you must write this as a Closed interval, because it includes the endpoints 5 and 12.
Therefore, knowing the above, you can write the set of all numbers from 5 to 12 inclusive, in Interval notation. Then, the answer is the following:
