Answer:
(C) Sample: the 120 students surveyed. Population: the 1200 students at the high school. Parameter of interest: the average number of hours a student at this high school sleeps per night.
Step-by-step explanation:
The correct answer is (C). The sample is a subset of the population, and the parameter is a characteristic of the population of interest. 
 
        
             
        
        
        
Answer:
A. 720 per hour
Step-by-step explanation:
1200+ <em>720</em> + 720 + <u>360</u> =3000
         <em>hr 1↑</em>+  hr 2↑ + <u>↑30 min</u>
 
        
             
        
        
        
Its B, cause it’s collinear