Question

The language arts teacher wants to know whether the students in the entire school prefer a debate or an speech. The teacher draws a random sample from the following groups:

All teachers in the school
All boys in each grade
All students in the speech club
All students in each grade
Which group best represents the population she should take a random sample from to get the best results for her survey? (5 points)

a
All teachers in the school

b
All boys in each grade

c
All students in the speech club

d
All students in each grade

Johnny wants to know how many students in his school enjoy watching science programs on TV. He poses this question to all 26 students in his science class and finds that 75% of his classmates enjoy watching science programs on TV. He claims that 75% of the school's student population would be expected to enjoy watching science programs on TV. Is Johnny making a valid inference about this population? (5 points)

a
Yes, it is a valid inference because his classmates make up a random sample of the students in the school

b
Yes, it is a valid inference because he asked all 26 students in his science class

c
No, it is not a valid inference because he asked all 26 students in his science class instead of taking a sample from his math class

d
No, it is not a valid inference because his classmates do not make up a random sample of the students in the school
A researcher posts a magazine advertisement offering $30 in exchange for participation in a short study. The researcher accepts the first three people who respond to the advertisement. Which of the following statements is true about the sample? (5 points)

a
It is not a valid sample because it is not a random sample of the population.

b
It is a valid sample because the first three people were selected to participate.

c
It is a valid sample because money was offered to participants.

d
It is not a valid sample because it is only a short study.

Answer 1

D, D,B, that’s what I think is right

Answer 2

Q1: D

Q2: D

Q3: B

Explanation:

Q1: It says it in the question.

Q2: He asked the ones in his science class so they would obviously prefer science, but that is not true for the rest of the students.

Q3: It is random because the first 3 people were chosen regardless of who they were, and it is still a valid sample even if the study is short.