Final answer:
The ratio of female students to all students in the freshman class is 5:9.
Step-by-step explanation:
To find the ratio of female students to all students, we need to find the number of female students in the freshman class. The given ratio of male students to female students is 4:5. So, let's assume the number of male students is 4x and the number of female students is 5x. The total number of students in the freshman class is given as 216. Therefore, 4x + 5x = 216, which simplifies to 9x = 216. Dividing both sides by 9, we find that x = 24. So, the number of female students is 5x = 5(24) = 120. The ratio of female students to all students is therefore 120:216, which simplifies to 5:9.