Question

A school conducted a survey to determine which sport was the students’ favorite. The school asked every seventh grade student for his or her favorite sport. Were the results of the school's survey valid?

A.
Yes, because every student in the seventh grade was surveyed.
B.
No, because the sample was not random.
C.
Yes, because the school surveyed every seventh student that entered the school.
D.
No, because only girls were surveyed.

Answer 1

B. No, because the sample was not random.

Explanation:

The survey asks to find the favourite sport of the school's students. Not just the school's seventh graders. The seventh graders do not make up a random sample of the student body, and therefore the results of this survey are invalid.

Let's look at the answers:

A - No. We've already discussed why sampling just the seventh graders is wrong.

B - Yes. The entire seventh grade is not a random sample of the entire school and do not yield a valid response.

C - No. The school surveyed every seventh grader, not every seventh student. This is a play on words.

D - No. Every student in the seventh grade was sampled, not just girls.