Homework answers / question archive / 1) What is a? population, what is a? sample, and what is the difference between? them? What is a? population? A

1) What is a? population, what is a? sample, and what is the difference between? them? What is a? population? A

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1) What is a? population, what is a? sample, and what is the difference between? them?

What is a? population?

A. A population is a characteristic found by summarizing raw data.

B. A population is the range of values that a parameter is likely to take.

C. A population is a portion of the entities of interest to a researcher that the researcher uses to gather data.

D. A population is the set of entities that are not contained in a sample.

E. A population is the entire group of entities of interest to a researcher.

2) What is a? sample?

A. A sample is a portion of the entities of interest that the researcher uses to gather data.

B. A sample is the range of values that a parameter is likely to take.

C. A sample is a characteristic found by summarizing raw data.

D. A sample is the entire group of entities of interest to a researcher.

E. A sample is the set of entities that are not contained in a population.

3) What is the difference between a population and a? sample?

A. If an entity is in the population then it cannot be in the sample.

B. A population is only a part of a complete sample.

C. A sample is only a part of a complete population.

D. If an entity is in the sample then it cannot be in the population.

E. There is no difference. A population and a sample are the same thing.

 

4) A poll is conducted the day before a state election for Senator. There are only two candidates running for this office. The poll results show that 56?%of the voters favor the Republican? candidate, with a margin of error of 4 percentage points. Should the Republican expect to? win? Why or why? not?

Choose the correct answer below.

A. The results suggest that the Republican is not likely to win a solid majority? because, when the margin of error is taken into? account, he or she will most likely not get the majority of the vote.

B. The results suggest that the Republican is just as likely to win or lose the election because

56?% is very close to? 50%.

C. The results suggest that the Republican is likely to win a solid majority because he or she will most likely get between 52% and 60?% of the vote.

 

5) In a? poll,1,004 adults in a certain country were asked whether they favor or oppose the use of? "federal tax dollars to fund medical research using stem cells obtained from human? embryos." Based on the poll? results, it is estimated that 45?% of adults are in? favor, with a margin of error of 3 percentage points. Use the given statistic and margin of error to identify the range of values? (confidence interval) likely to contain the true value of the population parameter.

 

The range of values likely to contain the population parameter is from

 

6) Cluster sampling and stratified sampling both involve selecting subjects in subgroups of the population. What is the difference between those two types of? sampling?

Choose the correct answer below.

A. With cluster? sampling, all members of randomly selected subgroups? (or clusters) are? selected, but with stratified? sampling, samples from each of the different subgroups? (or strata) are selected.

B. With cluster? sampling, samples from each of the different subgroups? (or clusters) are? selected, but with stratified? sampling, all members of randomly selected subgroups? (or strata) are selected.

C. With cluster? sampling, one member of the population is selected from each of the subgroups? (or clusters), but with stratified? sampling, more than one member of the population is selected from each of the subgroups? (or strata).

D. There is no difference between cluster and stratified sampling.

 

7) A researcher wants to determine the percentage given below. Describe how the researcher should apply the five basic steps in a statistical study.? (Assume that all the people in the poll answered? truthfully.)

the percentage of workplaces that have a water cooler

 

Determine how to apply the first basic step in a statistical study in this situation.

 

A. The population is all workplaces.  The researcher wants to estimate the percentage in this population that do not have a water cooler.

B. The population is all workplaces. The researcher wants to estimate the percentage in this population that

Have a water cooler.

C. The population is all workplaces that have a water cooler.  The researcher wants to estimate the percentage in this population that Have a water cooler.

D.The population is all workplaces that have a water cooler.  The researcher wants to estimate the number in this population that have a watercooler.

8) Determine how to apply the second basic step in a statistical study in this situation.

A. The researcher should only gather raw data from workplaces that have a water cooler.

B.The researcher should gather data about having a water cooler from the largest sample of workplaces that the researcher can gather data for.

C.The researcher should only gather raw data from workplaces that do not have a water cooler.

D.The researcher should gather raw data from all workplaces about whether or not they have a water cooler.

9) Determine how to apply the third basic step in a statistical study in this situation.

A.The sample statistic of interest is the percentage of workplaces that do not have a  water cooler in the population.

B.The sample statistic of interest is the percentage of workplaces that have a water cooler in the sample.

C.The sample statistic of interest is the number of workplaces that have a  water cooler in the sample.

D.The sample statistic of interest is the number of workplaces that do not have a water cooler in the population.

10) Determine how to apply the fourth basic step in a statistical study in this situation.

A.If the researcher followed correct? procedures, he or she can be confident that the sample statistic is equal to the percentage of workplaces in the population that have a watercooler

B.If the percentage of workplaces that have a water cooler is greater than? 50% in the? sample, the researcher can be confident that all workplaces have a water cooler.

C.The researcher should use the sample statistic as an estimate for the population value of the percentage of

Workplaces that have a water cooler and then use the methods of statistics to determine how good that estimate is.

D.The sample statistic provides no useful information to the researcher in this situation.

11) Determine how to apply the fifth basic step in a statistical study in this situation.

A.The researcher cannot draw any conclusions based on the value of the sample statistic.

B.The  researcher knows that the sample statistic is equal to the population? parameter, so he or she may draw conclusions with complete confidence.

C.The researcher should use the methods of statistics to determine the quality of the estimate of the population parameter and draw conclusions based on this estimate accordingly.

D.There is no way to determine how good an estimate the sample statistic is of the population parameter.

 

12) In a Gallup poll of 1,013 randomly selected American teachers?, ?89% said that cloning of humans should not be allowed. Identify the? sample, population, and sampling method. Then comment on whether you think it is likely that the sample is representative of the population.

 

Identify the sample. Choose the correct answer below.

A.The 1,013 randomly selected American teachers

B.all American teachers

C.Teachers of the whole world

D.89% of randomly selected American teachers

13) Identify the population. Choose the correct answer below.

A.Teachers of the whole world

B.89% of randomly selected American teachers

C.all American teachers

D.The 1,013 randomly selected American teachers

14) Identify the sampling method. Choose the correct answer below.

A.Systematic

B.Random

C.Convenience

15) Comment on whether you think it is likely that the sample is representative of the population. Choose the correct answer below.

A.The sample is fairly large and random. Assuming it was obtained by a reputable? firm, the sample is likely to be representative of the population.

B.The size of the sample is not equal to the size of the? population, so the sample is likely to be representative of the population.

C.The members of the sample have different characteristics than members of the? population, so the sample is not likely to be representative of the population.

16) A magazine ran a survey about a web site for downloading music.  Readers could register their responses on the? magazine's web site. Identify a source of bias in this study.

Choose the correct answer below.

A.Bias from the survey wording.

B.Bias from cluster sampling.

C.Bias from the survey funding source.

D.Bias from? self-selection.

17) A? nine-year-old tested professional touch therapists.  Using a cardboard? partition, she held a hand above one of the? therapist's hands, and the therapist was asked to identify the hand that was chosen.

What type of study is? this?  What are the variables of? interest?

Choose the correct answer below.

A.Experiment.  The variable of interest is the result of either correct or incorrect for each trial.

B.Experiment.  The variable of interest is which hand is chosen by the therapist for each trial.

C.Observational study.  The variable of interest is the result of either correct or incorrect for each trial.

D.Observational study.  The variable of interest is which hand is chosen by the therapist for each trial.

18) Newspaper asks its readers to call in their opinion regarding their taste in reading.

What type of sampling is? used?

A.Stratified

B.Convenience

C.Systematic

D.Cluster

E.Simple random

19) Decide whether the following statement makes sense? (or is clearly? true) or does not make sense? (or is clearly? false). Explain your reasoning.

My experiment proved beyond a doubt that vitamin C can reduce the severity of? colds, because I controlled the experiment carefully for every possible confounding variable.

Choose the correct answer below.

A.The statement makes sense because every possible confounding variable can be eliminated through careful study.

B.The statement does not make sense because it is not always easy to discover confounding variables.

C.The statement does not make sense because confounding variables would not affect the reliability of the experiment.

D.The statement makes sense because confounding variables are the only reason an? experiment's results could be doubted.

 

20) In testing the effectiveness of a new? vaccine, suppose that researchers used males for the treatment group and females for the placebo group. What is? confounding, and how would it affect such an? experiment?

What is? confounding?

A.Confounding is the process of making a sample more representative of the population.

B. Confounding is when the researchers and subjects in a study do not know who is in the treatment group and who is in the control group.

C. Confounding is the mixing of effects from different factors so that the effects from the specific factors being studied cannot be determined.

D.Confounding is the process of eliminating all differences between the groups in a study so that the only difference that remains is the factor of interest to the researcher.

21) How would it affect such an? experiment?

A.If males are given the treatment and females are given? placebos, a researcher would be certain that any differences between the two groups are attributable to the treatment.

B.Confounding would make the results of the experiment more representative of the population.

C.The researchers would be confounded as to whether the males or the females are receiving the treatment.

D.If males are given the treatment and females are given? placebos, a researcher would not know whether effects are due to the treatment or the sex of the participant.

22)  Politicians commonly believe that they must make their political statements? (often called? sound-bytes) very short because the attention span of listeners is so short. A similar effect occurs in reporting statistical news. Major statistical studies are often reduced to one or two sentences. A summary of a statistical? report, taken from a news? source, is given below. Describe what crucial information is missing in the given statement below and what more should be? known, before the report is acted on.

A newspaper reports on a poll claiming that the percentage of adults with a? "great deal of? confidence" in military leaders stands at? 54%.

A.The summary gives all of the pertinent information for interpreting the study.

B.The summary does not give a specific quantity for the amount of adults that have confidence in military leaders. It merely states that? "a great? deal" of adults have? 54% confidence in military? leaders, with no definition of? "a great? deal."

C.No information is given about how the researchers defined? "a great deal of? confidence" or how they asked questions about it. The sample size and margin of error are not provided.

D.The summary does not give enough information to determine whether the study was an observational study or an experiment.