Using proportions, it is found that 15 teachers will need to be hired to maintain the student : teacher ratio.
A proportion is a fraction of total amount, and the measures are related using a rule of three.
In this problem, the ratio means that 1 teacher is needed for 9 students. How many teachers are needed for 135 students?
The rule of three is:
1 teacher - 9 students
x teachers - 135 students
Applying cross multiplication:
[tex]9x = 135[/tex]
[tex]x = \frac{135}{9}[/tex]
[tex]x = 15[/tex]
15 teachers will need to be hired to maintain the student : teacher ratio.
To learn more about proportions, you can take a look at https://brainly.com/question/24372153
