Ateacher needs to find out how many seventh graders will be going on a field trip. which best describes the population that the teacher should survey?

All seventh graders.

Step-by-step explanation:

In statistics , the population is the set of all possible observations as per the researcher's objective .

For example if a researcher wants to find the average height of teenager of age group between 13 year and 15 years in Seattle, he will need the data of the population of height of teenager of age group between 13 year and 15 years in Seattle.

Here , A teacher needs to find out how many seventh graders will be going on a field trip.

Clearly as per her objective she need the data of all seventh graders .

So , the best describes the population that the teacher should survey would be : All seventh graders.