Answer:
The are 28 math majors in the class.
Step-by-step explanation:
We can solve this question using a rule of three.
The ratio of math majors to non math majors is 4 to 9
This means that 4+9 = 13 students, 4 are math majors.
The class has 91 students. How many are math majors?
13 students - 4 math majors
91 students - x math majors
![13x = 4*91](https://tex.z-dn.net/?f=13x%20%3D%204%2A91)
![x = \frac{4*91}{13}](https://tex.z-dn.net/?f=x%20%3D%20%5Cfrac%7B4%2A91%7D%7B13%7D)
![x = 28](https://tex.z-dn.net/?f=x%20%3D%2028)
The are 28 math majors in the class.