Question 16 options: Semi-annually Quarterly Monthly Question 17 (1 point) An 128GB iPhone costs $699.99 in 2016. The next year the cost of the iPhone was $629.99. The percentage change is: Question 17 options: -90% -10% +10% Question 18 (1 point) I A school cafeteria hands out a survey to 200 students to determine which items to add to the menu. What is the population being represented? Question 18 options: Only the students that buy food that day. Only the students that go home for lunch.