Chapter 11.3, Problem 40E

(a)

To determine

To find: the method of data collection

Answer to Problem 40E

The appropriate data collection method is survey.

Explanation of Solution

Given:

An airline wants to know whether the travelers have enough leg room on its plane.

Calculation:

In this case, the appropriate data collection method is survey.

A sample could be selected from the total population of travelers and then those who are surveyed can be asked question about leg space.

Conclusion:

Therefore, the appropriate data collection method is survey.

(b)

To determine

To find: a sampling method that is likely to give biased results.

Answer to Problem 40E

A cluster sampling is likely to give biased results.

Explanation of Solution

Calculation:

A cluster sampling is likely to give biased results. Airline travelers are divided into three groups First class, Business class and Economy class. Then all the members of the Business class are surveyed.

Then in such a case the result will be biased as the opinion about the leg space of travelers of other two classes might be different from that of the travelers of Business class.

Conclusion:

Therefore, a cluster sampling is likely to give biased results

(c)

To determine

To find: a sampling method that is not likely to give biased results.

Answer to Problem 40E

A stratified sampling is not likely to give biased results.

Explanation of Solution

Calculation:

A stratified sampling is not likely to give biased results. Airline travelers are divided into three groups First class, Business class and Economy class. Then a sample is surveyed from each of the three classes.

Such a sample would be the representative of the population and thus is likely to give an unblased result.

Conclusion:

Therefore, a stratified sampling is not likely to give biased results.

(d)

To determine

To write: one biased question and one unbiased question for this situation.

Answer to Problem 40E

Biased question: “Do you agree that there is enough leg room in the plane?”

Unbiased question: “Do you think there is enough leg room in the plane?”

Explanation of Solution

Calculation:

A biased question for this situation could be

“Do you agree that there is enough leg room in the plane?”

An unbiased question for this situation could be

“Do you think there is enough leg room in the plane?”.

Conclusion:

Biased question: “Do you agree that there is enough leg room in the plane?”

Unbiased question: “Do you think there is enough leg room in the plane?”