Answer:
The approximate absentee rate that day was of 8.1%.
Explanation:
The absentee rate can be calculated by the following formula:

In which
is the absentee rate,
is the number of students that were absent and
is the total number of numbers.
The problem states that:
On a given day, 36 of the 445 students in a school were absent
This means that:
and
.
So:

The approximate absentee rate that day was of 8.1%.