# Surveys: Biased Samples and Questions

1) Biased Sample: Find an example of a survey that used a biased sample. Explain why the sample is biased. What could have been done to make the sample unbiased? (Newspaper article, magazine, or Internet search) I have no idea of how to look for this. How do I know what is biased and how to make it unbiased?

2) Biased Survey Question: Find an example of a survey that used a biased survey question. Explain why the question is biased. Rewrite the survey question that is is unbiased or at least less biased. Help all of this is very confusing. I did not even begin the class yet. How can I explain all of it. I need to do this ahead of time, before the class begins. Please help.

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1. Biased Sample: Find an example of survey the used a biased sample. Explain why the sample is biased. What could have been done to make the sample unbiased? (Newspaper article, magazine, or Internet search)

In a USA Today call-in poll 81 percent of the more than 6,000 respondents said that "Donald Trump symbolizes what made the U.S.A. a great ...

#### Solution Summary

This solution discusses biased samples and questions in surveys.

Descriptive statistics: 18 multiple choice questions

Assignment: Week 1 Ch 1

1. A quality-control manager randomly selects 90 bottles of vinegar that were filled on September 21 to assess the calibration of the filling machine.

What is the population in the study?

A. Bottles of vinegar produced in the plant.

B. Bottles of vinegar produced in the plant on September 21.

C. The 90 bottles of vinegar produced in the plant on September 21.

D. The 90 bottles of vinegar produced in the plant.

What is the sample in the study?

A. The 90 bottles of vinegar produced in the plant in September.

B. Bottles of vinegar produced in the plant on September 21.

C. Bottles of vinegar produced in the plant.

D. The 90 bottles of vinegar in the plant on Sept. 21.

2. Determine whether the numerical value is a parameter or a statistic. Explain your reasoning.

A Survey of 42 out of hundreds in a dining hall showed that 17 enjoyed their meal.

Choose the correct answer below.

A. Statistic, because the data set of all people in the dining hall is a sample.

B. Parameter, because the data set of all people in the dining hall is a sample.

C. Parameter, because the data set of 42 people in a dining hall is a sample.

D. Statistic, because the data of 42 people in a dining hall is a sample.

E. Parameter, because the data set of all people in the dining hall is a population.

F. Statistic, because the data set of all people in the dining hall is a population.

G. Statistic, because the data set of 42 people in a dining hall is a population.

H. Parameter, because the data set of 42 people in a dining hall is a population.

3. Suppose a survey of 558 women in the United States found that more than 605 are the primary investor in their household. Which part of the survey represents the descriptive branch of statistic?

Make an inference based on the results of the Survey.

Choose the best statement of the descriptive statistic in the problem.

A. There is an association between the 558 women and being the primary investor in their household.

B. 538 women were surveyed

C. 60% of women in the sample are the primary investor in their household.

D. There is an association between the 538 women and being the primary investor in their household.

Choose the best inference from the given information.

A. 538 women were surveyed.

B. 60% of women in the sample are the primary investor in their household.

C. There is an association between the 538 women and being the primary investor in their household.

D. There is as association between U.S. women and being the primary investor in their household

4. A study shows that students in first grade are shorter than students in fourth grade.

(a) Make an inference based on the results of the study. Choose the correct answer below.

(b) What might this inference incorrectly imply?

A. Students in first grade have not taken enough vitamins to grow yet.

B. Students in first grade are younger than the students in fourth grade and have grown less.

C. Students in fourth grade are shorter than students in first grade.

D. Students in first grade are shorter than students in fourth grade.

(c) What might this inference imply?

A. This inference may incorrectly imply that if you switched to fourth grade, you would be shorter than you would be if you were in the first grade.

B. This inference may incorrectly imply that students in first grade have not taken enough vitamins to grow yet.

C. This inference may incorrectly imply that students in first grade are younger than the students in fourth grade and have grown less.

D. This inference may incorrectly imply that if you switched to the first grade, you would be shorter than you would be if you were in the fourth grade.

5. Determine whether the statement is true or false. If it is false, rewrite it as a true statement.

A population is the collection of some outcomes, responses, measurements, or counts that are of interest.

Choose the correct answer below.

A. True.

B. False. A population is the collection of all outcomes, responses, measurements, or counts that are interest.

C. False. A sample is the collection of all outcomes, responses, measurements, or counts that are of interest.

6. Determine whether the variable is qualitative or quantitative.

Distance in miles to nearest outdoor stadium.

Is the variable qualitative or quantitative?

( ) Qualitative

( ) Quantitative

7. The following appear on a physician's intake form. Identify the level of measurement of the data.

(a) Family history of illness

(b) Happiness level ( scale of 0 to 10)

(c) Temperature

(d) Time since last visit

(a) What is the level of measurement for "family history of illness"?

( ) Ordinal

( ) Interval

( ) Nominal

( ) Ratio

(b) What is the level of measurement for "Happiness level (scale of 0 t0 10)?

( ) Ordinal

( ) Ratio

( ) interval

( ) Nominal

(c) What is the level of measurement for Temperature"?

( ) Ordinal

( ) ratio

( ) Interval

( ) Nominal

(d) What is the level of measurement for "Time since last visit"?

( ) Interval

( ) Ration

( ) Nominal

( ) Ordinal

8. Determine whether the statement is true or false. If is false, rewrite it as a true statement.

More types of calculation can be performed with data at the interval level than with data at nominal level.

Choose the correct answer below.

( ) A. False. More types of calculations can be performed with data at interval level than with data at the nominal level

( ) B. True.

( ) C. False. The same types of calculations can be performed with data at the nominal level and with data at the interval level.

9. Decide which method of data collection you would use to collect data for the study

A study of the effect on the taste of a snack food made with a fat substitute.

Choose the correct answer below.

A. Simulation

B. Experiment

C. Survey

D. Observational Study

10. Decide which method of data collection you would use to collect data for the study described below.

A study of how fast a certain poison kills a human child.

Choose the correct answer.

A. Observational study

B. Simulation

C. Experiment

D. Survey

11. A Radio station asks its listeners to call in their opinion regarding the use of pesticides in residential areas.

What type of sampling is used?

A. Systematic

B. Simple random

C. Convenience

D. Stratified

E. Cluster

12. To determine customer opinion of their service, Business Depot randomly selects 120 stores during a certain week and surveys all customers present in the store.

What type of sampling is used?

A. Stratified

B. Convenience

C. Simple random

D. Systematic

E. Cluster

13. Nissan wants to administer a satisfaction survey to its current customers. Using their customer database, the company randomly selects 70 customers and asks them about their level of satisfaction with the company.

What type of sampling is used?

A. Cluster

B. Systematic

C. Simple random

D. Stratified

E. Convenience

14. To estimate the percentage of defects in a recent manufacturing batch, a quality control manager at General Foods selects every 20th soup can that comes of the assembly line starting with the tenth until she obtains a sample of 60 soup cans.

What type of sampling is used/

A. Cluster

B. Systematic

C. Simple random

D. Convenience

E. Stratified

15. To determine her blood pressure, Jean divides up her day into three parts, morning, afternoon, and evening. She then measures her blood pleasure at 3 randomly selected times during each part of the day.

What type of sampling is used?

A. Stratified

B. Convenience

C. Simple random

D. Systematic

E. Cluster

16. Determine whether you would take a census or use sampling to collect data for the study described below.

The most popular house color among the 20 employees of a company.

Would you take a census or use a sampling?

( ) Census

( ) Sampling

17. Determine whether the survey question is biased. If the question is biased, suggest a better wording.

Why is eating eggs bad for you?

Is the question biased?

( ) No

( ) Yes

If the question is biased, which question below is worded better?

A. Do you think that eating eggs is bad for you?

B. How do you think eating eggs affects your health?

C. The original question is not biased.

D. Why is eating eggs good for you/

E. Do you think that eating eggs is good for you?

18. Determine whether the statement is true or false. If it is false, rewrite it as a true statement.

The method for selecting a stratified sample is to order a population in some way and then select members of the population at regular intervals.

Choose the correct answer below.

A. True

B. False. The method for selecting a systematic sample is to order a population in some way and then select members of the population at regular intervals.

C. False. The method for selecting a cluster sample is to order a population in some way and then select members of the population at regular intervals.