Chapter PV, Problem 19RE

(a)

To determine

To find out did they describe the five W’s well.

Answer to Problem 19RE

Yes, they did well.

Explanation of Solution

It is given in the question that a newspaper article that reported the results of an election poll included the following explanation. Thus, yes, they describe the five W’s well as,

Who: Around $798$ registered voters of all states except Alaska and Hawaii.

What: Voter’s age, sex, region and education.

When: During $2012$ presidential campaign.

Where: America.

Why: Not reported.

(b)

To determine

To find out what kind of sampling design could take into account the several demographic factors listed.

Answer to Problem 19RE

It is stratified sampling.

Explanation of Solution

It is given in the question that a newspaper article that reported the results of an election poll included the following explanation. Thus, the sampling design could take into account the several demographic factors listed is the stratified sampling as the sample was divided in to the strata and they the study was conducted.

(c)

To determine

To find out what was the margin of error.

Answer to Problem 19RE

The margin of error is $\pm 4\%$ .

Explanation of Solution

It is given in the question that a newspaper article that reported the results of an election poll included the following explanation. As it is given that no more than one time in $20$ should chance variations in the sample cause the results to vary by more than $4$ percentage points from the answers that would be obtained if all Americans were polled. Thus, the margin of error is $\pm 4\%$ .

(d)

To determine

To find out what was the confidence level.

Answer to Problem 19RE

Confidence level is $95\%$ .

Explanation of Solution

It is given in the question that a newspaper article that reported the results of an election poll included the following explanation. As we know from the results that the margin of sampling error is larger for responses of subgroups, such as income categories or those in political parties. Thus, we can assume the normal confidence level that is $95\%$ .

(e)

To determine

To explain why is the margin of error larger for subgroups.

Explanation of Solution

It is given in the question that a newspaper article that reported the results of an election poll included the following explanation. Thus, as we know from the results that the margin of sampling error is larger for responses of subgroups, such as income categories or those in political parties. There are others sources of potential error in polling including the wording and order of questions. Therefore, it is higher as the sample sizes are smaller for which the study was conducted.

(f)

To determine

To explain which kind of potential bias did they caution readers about.

Answer to Problem 19RE

The bias is the wordings and question orders.

Explanation of Solution

It is given in the question that a newspaper article that reported the results of an election poll included the following explanation. As the results that the margin of sampling error is larger for responses of subgroups, such as income categories or those in political parties and there are others sources of potential error in polling including the wording and order of questions. Thus, the bias is the wordings and question orders.