Chapter 12, Problem 17E

(a)

To determine

To indicate what kind of sampling strategy is involved and what bias might result.

Answer to Problem 17E

The sampling strategy used in this idea is voluntary response.

Explanation of Solution

It is given in the question that in a large school system with twenty elementary schools, the school board is considering the adoption of a new policy that would require elementary students to pass a test in order to promoted to next grade. The ideas proposed for gathering data is given as: Put a big as in the newspaper asking people to log their opinions on the PTA website. Thus, the kind of sampling strategy used in this idea is voluntary response. And the bias might result because only those who see the ad, have internet access and feel strongly enough will respond.

(b)

To determine

To indicate what kind of sampling strategy is involved and what bias might result.

Answer to Problem 17E

The sampling strategy used in this idea is cluster sampling.

Explanation of Solution

It is given in the question that in a large school system with twenty elementary schools, the school board is considering the adoption of a new policy that would require elementary students to pass a test in order to promoted to next grade. The ideas proposed for gathering data is given as: randomly select one of the elementary schools and contact every parent by phone. Thus, the kind of sampling strategy used in this idea is cluster sampling. The bias might occur in this method because one school may not be typical of all other.

(c)

To determine

To indicate what kind of sampling strategy is involved and what bias might result.

Answer to Problem 17E

The sampling strategy used in this idea is attempted census.

Explanation of Solution

It is given in the question that in a large school system with twenty elementary schools, the school board is considering the adoption of a new policy that would require elementary students to pass a test in order to promoted to next grade. The ideas proposed for gathering data is given as: Send a survey home with every student and ask parents to fill out and return it the next day. Thus, the kind of sampling strategy used in this idea is attempted census. And the biasness will occur in this method because it will have non-response biasness.

(d)

To determine

To indicate what kind of sampling strategy is involved and what bias might result.

Answer to Problem 17E

The sampling strategy used in this idea is stratified sampling.

Explanation of Solution

It is given in the question that in a large school system with twenty elementary schools, the school board is considering the adoption of a new policy that would require elementary students to pass a test in order to promoted to next grade. The ideas proposed for gathering data is given as: Randomly select twenty parents from each elementary school. Send them a survey, and follow-up with a phone call if they do not return the survey within a week. Thus, the kind of sampling strategy used in this idea is stratified sampling. And the biasness will occur in this method because with the stratified sampling we will do follow-up which will lead to un-biasness.