Question

A middle school contains sixth, seventh, and eighth graders. Each grade level contains approximately the same number of students. The principal wants to find the answer to a survey question affecting each student in the school. He asks a sample group "What time do you get up in the morning?" Which of these characteristics define the best sample?

Answer 1

one student chosen at random from each grade level

(A)

Explanation:

Answer 2

the options are missing, so I looked for a similar question and found these options:

• one student chosen at random from each grade level
• an equal number of students chosen at random from each grade level
• the first 10 students from each grade level to arrive at school in the morning
• all students arriving on one bus

the answer is: an equal number of students chosen at random from each grade level

Explanation:

A good sample must be random and representative of all the population. In this case, the population is all the kids that go to middle school. A good sample would need to be taken at random and all the students should have equal opportunity to be chosen, and the three grades must be included in the same proportion.