2880 ...................................
Answer:
9. representative because she samples a small group of people to gather representative data for a larger group
10. biased because hes asking people their favorite (opinionated word) sport at a sports game. people at that game most likely are there because it is their favorite
11. 9 students
12. median = 11
The answer would look something like this:

There could also have a simplified version.
I hope this helps.
Answer:
D
Step-by-step explanation:
I don't know how to eliminate the wrong answers.
Two line segments which have one end at a diameter and the other end meeting at a common point, make a 90 degree angle.
A is made that way, so A is 90 degrees.