Final answer:
The total number of students in Collins Middle School is 600.
Step-by-step explanation:
Given that the sixth grade is 30% of the total school, we can set up the equation:
0.30 * total number of students = 180
To find the total number of students, we divide both sides of the equation by 0.30:
total number of students = 180 / 0.30
Simplifying the equation, we get:
total number of students = 600
Therefore, there are 600 students in the middle school.