qu.1.topic=Introduction to Statistics@

qu.1.1.mode=Inline@
qu.1.1.name=Magazine Study; Determine sampling method used.@
qu.1.1.comment=<p>a)&nbsp; This is an example of <em>Voluntary Response Sampling</em>, in which the sample is obtained through experimental units (i.e. readers) voluntarily responding to a survey.</p>
<p>&nbsp;</p>
<p>b)&nbsp; No, the claims of the cosmetic company's ad would not be considered representative of the entire female population.&nbsp; This is because the sample on which the claim is based is not a random sample from the entire female population, but instead is a sample of select women who opted to respond to a mail-in survey.</p>@
qu.1.1.editing=useHTML@
qu.1.1.solution=@
qu.1.1.algorithm=@
qu.1.1.uid=f7df7cc7-4118-4185-9aca-3938ed291dc7@
qu.1.1.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Medium;
  Features=None;
  Type=Concept;
@
qu.1.1.weighting=1,1@
qu.1.1.numbering=alpha@
qu.1.1.part.1.grader=exact@
qu.1.1.part.1.name=sro_id_1@
qu.1.1.part.1.editing=useHTML@
qu.1.1.part.1.display.permute=true@
qu.1.1.part.1.answer.4=Representative Sampling@
qu.1.1.part.1.answer.3=Stratified Random Sampling@
qu.1.1.part.1.question=(Unset)@
qu.1.1.part.1.answer.2=Simple Random Sampling@
qu.1.1.part.1.answer.1=Voluntary Response Sampling@
qu.1.1.part.1.mode=List@
qu.1.1.part.1.display=menu@
qu.1.1.part.1.credit.4=0.0@
qu.1.1.part.1.credit.3=0.0@
qu.1.1.part.1.credit.2=0.0@
qu.1.1.part.1.credit.1=1.0@
qu.1.1.part.2.name=sro_id_2@
qu.1.1.part.2.editing=useHTML@
qu.1.1.part.2.fixed=@
qu.1.1.part.2.question=null@
qu.1.1.part.2.choice.2=No@
qu.1.1.part.2.choice.1=Yes@
qu.1.1.part.2.mode=Non Permuting Multiple Choice@
qu.1.1.part.2.display=horizontal@
qu.1.1.part.2.answer=2@
qu.1.1.question=<p>a)&nbsp; A cosmetic company's ad in a popular women's magazine claims that 80% of women find their lipstick to be the longest-lasting lipstick they have ever used.&nbsp; Upon reading the fine print, you discover that&nbsp;those results are based on 1200 mail-in surveys.</p><p>&nbsp;</p><p>The&nbsp;kind of sampling method employed by the cosmetic company&nbsp;was:&nbsp;<span>&nbsp;</span><1><span>&nbsp;</span>&nbsp;</p><p>&nbsp;</p><p>&nbsp;</p><p>b)&nbsp; Would the claims of the cosmetic company's ad be considered representative of the entire female population?</p><p>&nbsp;<span>&nbsp;</span><2><span>&nbsp;</span></p>@

qu.1.2.mode=Matching@
qu.1.2.name=Farming Study; Match: Population, Parameter, Sample, Statistic@
qu.1.2.comment=<p>A&nbsp;<em>population</em> is the set of all experimental units of interest to the researcher; here, it is all the corn plants.</p>
<p>A <em>sample</em> is a subset of the population, which in this case is the 50 corn plants randomly selected by the farmer.</p>
<p>A <em>parameter</em> is a characteristic of the population.&nbsp; Since the population is all the corn plants, the parameter is the mean weight of all the corn plants.</p>
<p>A <em>statistic</em> is a characteristic of the sample.&nbsp; Since the sample consisted of&nbsp;50 randomly selected corn plants, the statistic is the mean weight of the&nbsp;50 corn plants&nbsp;in the sample.</p>@
qu.1.2.editing=useHTML@
qu.1.2.solution=@
qu.1.2.algorithm=@
qu.1.2.uid=a7159200-2d5e-4cdc-a98a-467c4df7c60a@
qu.1.2.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Easy;
  Features=None;
  Type=Concept;
@
qu.1.2.format.columns=4@
qu.1.2.question=<p>A farmer wants to estimate the average weight of corn produced by her crop.&nbsp; She decides that at the peak of growning season, she will randomly select 50 corn plants out of her entire crop and weigh the amount of corn they have produced.</p>
<p>&nbsp;</p>
<p>Match each of the numbered items in the list with the numbers in the drop-down menus:</p>@
qu.1.2.term.1=Statistic@
qu.1.2.term.1.def.1=Weight of 50 corn plants.@
qu.1.2.term.2=Parameter@
qu.1.2.term.2.def.1=Weight of all the corn plants.@
qu.1.2.term.3=Population@
qu.1.2.term.3.def.1=All the corn plants.@
qu.1.2.term.4=Sample@
qu.1.2.term.4.def.1=50 corn plants.@

qu.1.3.mode=Multiple Selection@
qu.1.3.name=Definitions 1: Sampling methods and Variables@
qu.1.3.comment=@
qu.1.3.editing=useHTML@
qu.1.3.solution=@
qu.1.3.algorithm=@
qu.1.3.uid=cec3afc5-15be-4a5a-acbf-871c0f0851c1@
qu.1.3.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Features=None;
  Difficulty=Easy;
  Type=Concept;
@
qu.1.3.question=<p>Which of the following statements are true?</p>
<p>&nbsp;</p>
<p>Note that there may be more than one correct answer; select all that are true.</p>@
qu.1.3.answer=1, 2@
qu.1.3.choice.1=Assuming a large population, in simple random sampling each individual in the population has the same probability of being selected.@
qu.1.3.choice.2=A survey is a type of observational study.@
qu.1.3.choice.3=A single observational study is efficient at identifying and controlling for lurking variables.@
qu.1.3.choice.4=If an explanatory variable and a response variable are correlated, then it can safely be assumed that the explanatory variable causes the response variable@
qu.1.3.choice.5=Changes in the response variable can either explain or cause changes in the explanatory variable.@
qu.1.3.fixed=@

qu.1.4.mode=True False@
qu.1.4.name=Determine if correlation implies causation@
qu.1.4.comment=<p><em>FALSE.</em></p>
<p>Correlation does not imply causation, particularly if there exists the possibility of lurking variables that may create the appearance of a relationship between the explanatory and response variables.</p>@
qu.1.4.editing=useHTML@
qu.1.4.solution=@
qu.1.4.algorithm=@
qu.1.4.uid=1258eeb6-6db4-4110-a831-64c3fac718f5@
qu.1.4.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Easy;
  Features=None;
@
qu.1.4.question=<p>If an explanatory variable and a response variable are correlated, then it can safely be assumed that the explanatory variable <em>causes</em> the response variable.</p>@
qu.1.4.answer=2@
qu.1.4.choice.1=True@
qu.1.4.choice.2=False@
qu.1.4.fixed=@

qu.1.5.mode=True False@
qu.1.5.name=Definition of an experiment@
qu.1.5.comment=<p><em>FALSE</em>.</p>
<p>In an experiment, researchers <em>DO</em> impose conditions on the experimental units.</p>@
qu.1.5.editing=useHTML@
qu.1.5.solution=@
qu.1.5.algorithm=@
qu.1.5.uid=32c0a49c-3a6d-4b5d-acbb-fd71539a9096@
qu.1.5.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Easy;
  Features=None;
@
qu.1.5.question=<p>In an experiment, researchers do not impose any conditions on the experimental units.</p>@
qu.1.5.answer=2@
qu.1.5.choice.1=True@
qu.1.5.choice.2=False@
qu.1.5.fixed=@

qu.1.6.mode=Inline@
qu.1.6.name=Toxicologist Study; Select Experiment, Observational or Survey@
qu.1.6.comment=<p>This type of study is an e<em>xperiment</em>, as the researcher imposed conditions on the experimental units by&nbsp;randomly selects certain fields to be assigned to one of two possible treatments.</p>@
qu.1.6.editing=useHTML@
qu.1.6.solution=@
qu.1.6.algorithm=@
qu.1.6.uid=f5124cae-5818-4b91-88db-f586a3c63595@
qu.1.6.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Easy;
  Features=None;
  Type=Concept;
@
qu.1.6.weighting=1@
qu.1.6.numbering=alpha@
qu.1.6.part.1.grader=exact@
qu.1.6.part.1.name=sro_id_1@
qu.1.6.part.1.editing=useHTML@
qu.1.6.part.1.display.permute=true@
qu.1.6.part.1.answer.3=Survey@
qu.1.6.part.1.question=(Unset)@
qu.1.6.part.1.answer.2=Observational Study@
qu.1.6.part.1.answer.1=Experiment@
qu.1.6.part.1.mode=List@
qu.1.6.part.1.display=menu@
qu.1.6.part.1.credit.3=0.0@
qu.1.6.part.1.credit.2=0.0@
qu.1.6.part.1.credit.1=1.0@
qu.1.6.question=<p>A toxicologist is interested in examining the effects of a new fungicide on controlling the presence of early-blight in tomato crops in southwestern Ontario.&nbsp; He randomly selects 25 tomato fields to be treated with the new fungicide, and 25 tomato fields to be left untreated.&nbsp; The toxicologist then estimates the average number of plants affected by early blight on each field.</p><p>&nbsp;</p><p>This type of study could best be described as a:&nbsp;<span>&nbsp;</span><1><span>&nbsp;</span></p>@

qu.1.7.mode=Multiple Choice@
qu.1.7.name=Determine best definition of Selection Bias@
qu.1.7.comment=<p><em>Selection bias</em> can often occur in surveys, when certain individuals are systematically excluded from the study.</p>
<p>For example, in a telephone survey based on phone numbers randomly selected from the phone book, individuals who do not have a phone, or who have unlisted numbers, are excluded from the survey, which can create a selection bias.</p>@
qu.1.7.editing=useHTML@
qu.1.7.solution=@
qu.1.7.algorithm=@
qu.1.7.uid=3acfa87f-99d4-476a-a71e-8e7b2b166dd8@
qu.1.7.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Medium;
  Features=None;
  Type=Concept;
@
qu.1.7.question=<p><em>Selection bias</em>&nbsp; is best defined as:</p>@
qu.1.7.answer=3@
qu.1.7.choice.1=The bias that can occur in an experiment, when the experimental units are given the opportunity to select their treatment.@
qu.1.7.choice.2=The bias that can occur when selecting the strata in a stratified random sample.@
qu.1.7.choice.3=The bias that can occur in surveys, when certain individuals are systematically excluded from the study.@
qu.1.7.choice.4=The bias that can occur in simple random sampling, when selecting the experimental units to participate in the study.@
qu.1.7.choice.5=The bias that can occur in surveys, when selecting which questions to ask the participants.@
qu.1.7.fixed=@

qu.1.8.mode=True False@
qu.1.8.name=Determine if survey is type of observational study@
qu.1.8.comment=<p><em>TRUE</em>.</p>
<p>A survey is a type of observational study, as the researchers simply observe a response, without imposing any kind of conditions on the experimental units.</p>@
qu.1.8.editing=useHTML@
qu.1.8.solution=@
qu.1.8.algorithm=@
qu.1.8.uid=7f70b88e-2b6b-4f8e-8276-d9c0aa54b432@
qu.1.8.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Easy;
  Features=None;
@
qu.1.8.question=<p>A survey is a type of observational study.</p>@
qu.1.8.answer=1@
qu.1.8.choice.1=True@
qu.1.8.choice.2=False@
qu.1.8.fixed=@

qu.1.9.mode=True False@
qu.1.9.name=Determine if response variable influences explanatory variable@
qu.1.9.comment=<p><em>FALSE</em>.</p>
<p>It is the explanatory variable that can either explain or cause changes in the response variable.</p>@
qu.1.9.editing=useHTML@
qu.1.9.solution=@
qu.1.9.algorithm=@
qu.1.9.uid=cdf2c956-013b-42f8-bd9e-cbf3804c5749@
qu.1.9.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Easy;
  Features=None;
@
qu.1.9.question=<p>Changes in the response variable can either explain or cause changes in the explanatory variable.</p>@
qu.1.9.answer=2@
qu.1.9.choice.1=True@
qu.1.9.choice.2=False@
qu.1.9.fixed=@

qu.1.10.mode=Inline@
qu.1.10.name=Marketing Study; Select Experiment, Observational, Survey@
qu.1.10.comment=<p>A <em>survey</em> of female shoppers in the department store would be the most effective way for the marketer to determine what scent of air freshener is preferred.</p>@
qu.1.10.editing=useHTML@
qu.1.10.solution=@
qu.1.10.algorithm=@
qu.1.10.uid=6bf2a3c1-46da-4720-87f6-6aac28eac120@
qu.1.10.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Easy;
  Features=None;
  Type=Concept;
@
qu.1.10.weighting=1@
qu.1.10.numbering=alpha@
qu.1.10.part.1.grader=exact@
qu.1.10.part.1.name=sro_id_1@
qu.1.10.part.1.editing=useHTML@
qu.1.10.part.1.display.permute=true@
qu.1.10.part.1.answer.3=Observational Study@
qu.1.10.part.1.question=(Unset)@
qu.1.10.part.1.answer.2=Experiment@
qu.1.10.part.1.answer.1=Survey@
qu.1.10.part.1.mode=List@
qu.1.10.part.1.display=menu@
qu.1.10.part.1.credit.3=0.0@
qu.1.10.part.1.credit.2=0.0@
qu.1.10.part.1.credit.1=1.0@
qu.1.10.question=<p>A marketer for a department store company is interested in determining what scent of air freshener is most popular among female shoppers.</p><p>&nbsp;</p><p>This type of study would best be investigated through a:&nbsp;<span>&nbsp;</span><1><span>&nbsp;</span></p>@

qu.1.11.mode=Inline@
qu.1.11.name=Police Study; Select Experiment, Observational, Survey@
qu.1.11.comment=<p>An&nbsp;<em>observational study</em>&nbsp;would be the most effective way for the&nbsp;police to determine the number of speeding drivers on a local stretch of highway.</p>@
qu.1.11.editing=useHTML@
qu.1.11.solution=@
qu.1.11.algorithm=@
qu.1.11.uid=910dd41a-dcbe-42d7-a98f-fa93eeed7d48@
qu.1.11.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Easy;
  Features=None;
  Type=Concept;
@
qu.1.11.weighting=1@
qu.1.11.numbering=alpha@
qu.1.11.part.1.grader=exact@
qu.1.11.part.1.name=sro_id_1@
qu.1.11.part.1.editing=useHTML@
qu.1.11.part.1.display.permute=true@
qu.1.11.part.1.answer.3=Observational Study@
qu.1.11.part.1.question=(Unset)@
qu.1.11.part.1.answer.2=Experiment@
qu.1.11.part.1.answer.1=Survey@
qu.1.11.part.1.mode=List@
qu.1.11.part.1.display=menu@
qu.1.11.part.1.credit.3=1.0@
qu.1.11.part.1.credit.2=0.0@
qu.1.11.part.1.credit.1=0.0@
qu.1.11.question=<p>On a holiday weekend, the police are interested in estimating the number of speeding drivers on a local stretch of highway.</p><p>&nbsp;</p><p>This type of study would best be investigated through a:&nbsp;<span>&nbsp;</span><1><span>&nbsp;</span></p>@

qu.1.12.mode=True False@
qu.1.12.name=Advantage of stratified random sampling@
qu.1.12.comment=<p><em>TRUE</em>.</p>
<p>By dividing the population into strata (i.e. groups), and then taking a random sample from within each strata, we can ensure that each strata is represented in the overall sample.</p>@
qu.1.12.editing=useHTML@
qu.1.12.solution=@
qu.1.12.algorithm=@
qu.1.12.uid=60602582-b1f0-4c67-a8c9-7f7225d68653@
qu.1.12.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Easy;
  Features=None;
@
qu.1.12.question=<p>One advantage of stratified random sampling is to ensure that each strata gets adequate representation in the sample.</p>@
qu.1.12.answer=1@
qu.1.12.choice.1=True@
qu.1.12.choice.2=False@
qu.1.12.fixed=@

qu.1.13.mode=Inline@
qu.1.13.name=Plant Sterols Study; Match response/explanatory variable, experimental unit@
qu.1.13.comment=<p>a)&nbsp; The <em>experimental unit</em> is the object or individual on which the measurement is being taken.&nbsp; Here, the experimental unit is the adult male.</p>
<p>The <em>response variable</em> is the outcome of the study that is of interest to the researcher.&nbsp; Here, the response variable is the cholesterol level.</p>
<p>The <em>explanatory variable</em> causes or explains the response variable.&nbsp; Here, the explanatory variable is the presence or absence of plant sterols.</p>
<p>&nbsp;</p>
<p>b)&nbsp; This type of variable is known as a <em>lurking variable</em>, which is an underlying or unaccounted for variable that could have an effect on the response.</p>@
qu.1.13.editing=useHTML@
qu.1.13.solution=@
qu.1.13.algorithm=@
qu.1.13.uid=8af9cd78-adfc-448b-bd4f-68aef7cbfc58@
qu.1.13.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Easy;
  Features=None;
  Type=Concept;
@
qu.1.13.weighting=1,1,1,1@
qu.1.13.numbering=alpha@
qu.1.13.part.1.grader=exact@
qu.1.13.part.1.name=sro_id_1@
qu.1.13.part.1.editing=useHTML@
qu.1.13.part.1.display.permute=true@
qu.1.13.part.1.answer.3=Presence or absence of plant sterols@
qu.1.13.part.1.question=(Unset)@
qu.1.13.part.1.answer.2=Cholesterol level@
qu.1.13.part.1.answer.1=Adult male@
qu.1.13.part.1.mode=List@
qu.1.13.part.1.display=menu@
qu.1.13.part.1.credit.3=0.0@
qu.1.13.part.1.credit.2=0.0@
qu.1.13.part.1.credit.1=1.0@
qu.1.13.part.2.grader=exact@
qu.1.13.part.2.name=sro_id_2@
qu.1.13.part.2.editing=useHTML@
qu.1.13.part.2.display.permute=true@
qu.1.13.part.2.answer.3=Presence or absence of plant sterols@
qu.1.13.part.2.question=(Unset)@
qu.1.13.part.2.answer.2=Cholesterol level@
qu.1.13.part.2.answer.1=Adult male@
qu.1.13.part.2.mode=List@
qu.1.13.part.2.display=menu@
qu.1.13.part.2.credit.3=0.0@
qu.1.13.part.2.credit.2=1.0@
qu.1.13.part.2.credit.1=0.0@
qu.1.13.part.3.grader=exact@
qu.1.13.part.3.name=sro_id_3@
qu.1.13.part.3.editing=useHTML@
qu.1.13.part.3.display.permute=true@
qu.1.13.part.3.answer.3=Presence or absence of plant sterols@
qu.1.13.part.3.question=(Unset)@
qu.1.13.part.3.answer.2=Cholesterol level@
qu.1.13.part.3.answer.1=Adult male@
qu.1.13.part.3.mode=List@
qu.1.13.part.3.display=menu@
qu.1.13.part.3.credit.3=1.0@
qu.1.13.part.3.credit.2=0.0@
qu.1.13.part.3.credit.1=0.0@
qu.1.13.part.4.grader=exact@
qu.1.13.part.4.name=sro_id_4@
qu.1.13.part.4.editing=useHTML@
qu.1.13.part.4.display.permute=true@
qu.1.13.part.4.answer.3=Influential variable@
qu.1.13.part.4.question=(Unset)@
qu.1.13.part.4.answer.2=Response-Bias variable@
qu.1.13.part.4.answer.1=Lurking variable@
qu.1.13.part.4.mode=List@
qu.1.13.part.4.display=menu@
qu.1.13.part.4.credit.3=0.0@
qu.1.13.part.4.credit.2=0.0@
qu.1.13.part.4.credit.1=1.0@
qu.1.13.question=<p>a)&nbsp; Researchers are setting up an experiment to determine the effect of plant sterols on lowering cholesterol in adult males.&nbsp; They randomly assign 50 males to a group that is given plant sterols, and 50 males to a group that is given a placebo.&nbsp; They measure each male's cholesterol level at the beginning of the experiment, and again 4 weeks later.</p><p>&nbsp;</p><p>Identify the experimental unit, the response variable, and the explanatory variable:</p><p>&nbsp;</p><p><span>&nbsp;</span><1><span>&nbsp;</span> is the experimental unit.</p><p><span>&nbsp;</span><2><span>&nbsp;</span> is the response variable.</p><p><span>&nbsp;</span><3><span>&nbsp;</span> is the explanatory variable.</p><p>&nbsp;</p><p>&nbsp;</p><p>b)&nbsp; The researchers neglected to account for the activity level of each male, which could have an effect on the outcome of the experiment.</p><p>This type of variable is known as a:&nbsp;<span>&nbsp;</span><4><span>&nbsp;</span></p>@

qu.1.14.mode=True False@
qu.1.14.name=Definition of response variable@
qu.1.14.comment=<p><em>TRUE</em>.</p>
<p>The response variable is the outcome of the study or experiment that is of interest to the researchers; it is what a researcher is interested in measuring.</p>@
qu.1.14.editing=useHTML@
qu.1.14.solution=@
qu.1.14.algorithm=@
qu.1.14.uid=c0460abf-3aaa-4ac8-b7ca-f15fd8952261@
qu.1.14.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Easy;
  Features=None;
@
qu.1.14.question=<p>A response variable is the outcome of the experiment or study.</p>@
qu.1.14.answer=1@
qu.1.14.choice.1=True@
qu.1.14.choice.2=False@
qu.1.14.fixed=@

qu.1.15.mode=Inline@
qu.1.15.name=Veterinary Epidemiologist; Select sampling method used@
qu.1.15.comment=<p>This is an example of <em>stratified random sampling</em>, in which the veterinary epidemiologist takes a random sample of experimental units from within each stratum (i.e. each classification&nbsp;level).</p>@
qu.1.15.editing=useHTML@
qu.1.15.solution=@
qu.1.15.algorithm=@
qu.1.15.uid=f42c41ad-99a1-49ad-92f0-eba7568951b8@
qu.1.15.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Medium;
  Features=None;
  Type=Concept;
@
qu.1.15.weighting=1@
qu.1.15.numbering=alpha@
qu.1.15.part.1.grader=exact@
qu.1.15.part.1.name=sro_id_1@
qu.1.15.part.1.editing=useHTML@
qu.1.15.part.1.display.permute=true@
qu.1.15.part.1.answer.4=Representative Sampling@
qu.1.15.part.1.answer.3=Stratified Random Sampling@
qu.1.15.part.1.question=(Unset)@
qu.1.15.part.1.answer.2=Simple Random Sampling@
qu.1.15.part.1.answer.1=Voluntary Response Sampling@
qu.1.15.part.1.mode=List@
qu.1.15.part.1.display=menu@
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qu.1.15.part.1.credit.3=1.0@
qu.1.15.part.1.credit.2=0.0@
qu.1.15.part.1.credit.1=0.0@
qu.1.15.question=<p>A veterinary epidemiologist wishes to investigate the use of antibiotics on cattle farms in southern Alberta.&nbsp; However, cattle farms in Alberta can be classified as either small, medium, or large farms, depending on how many cattle are present.&nbsp; The epidemiologist decides to randomly sample farms within each classification level.</p><p>&nbsp;</p><p>This type of sampling method is best described as:&nbsp;<span>&nbsp;</span><1><span>&nbsp;</span></p>@

qu.1.16.mode=True False@
qu.1.16.name=Determine if observational studies can control lurking variables@
qu.1.16.comment=<p><em>FALSE</em>.</p>
<p>Because in an observational study no conditions are imposed on the experimental units, and researchers simply observe the response variable, observational studies are not efficient at identifying and controlling for lurking variables.</p>@
qu.1.16.editing=useHTML@
qu.1.16.solution=@
qu.1.16.algorithm=@
qu.1.16.uid=75b1c26a-6b55-4428-9307-dcbac1f07a89@
qu.1.16.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Easy;
  Features=None;
@
qu.1.16.question=<p>A single observational study is efficient at identifying and controlling for lurking variables.</p>@
qu.1.16.answer=2@
qu.1.16.choice.1=True@
qu.1.16.choice.2=False@
qu.1.16.fixed=@

qu.1.17.mode=Inline@
qu.1.17.name=Definitions 1&2 Combined: Random selection of True/False statements.@
qu.1.17.comment=@
qu.1.17.editing=useHTML@
qu.1.17.solution=@
qu.1.17.algorithm=$k1=rint(10);
$k2=rint(10);
$k3=rint(10);
$k4=rint(10);
$k5=rint(10);
$z=maple("S := $k1,$k2,$k3,$k4,$k5:
floor( nops({S})/nops([S]) )");
condition: $z;
$a=("'Assuming a large population, in simple random sampling each individual in the population has the same probability of being selected.'");
$b=("'A survey is a type of observational study.'");
$c=("'One advantage of stratified random sampling is to ensure that each strata gets adequate representation in the sample.'");
$d=("'A response variable is the outcome of the experiment or study.'");
$e=("'In a well-designed experiment, it may be possible to show a causal relationship between the explanatory variable and the response variable.'");
$f=("'A single observational study is efficient at identifying and controlling for lurking variables.'");
$g=("'If an explanatory variable and a response variable are correlated, then it can safely be assumed that the explanatory variable causes the response variable.'");
$h=("'Changes in the response variable can either explain or cause changes in the explanatory variable.'");
$i=("'In an experiment, researchers do not impose any conditions on the experimental units.'");
$j=("'Sampling methods other than simple random sampling are always free of strong biases.'");
$Answers=["'True'","'True'","'True'","'True'","'True'","'False'","'False'","'False'","'False'","'False'"];
$Distractors=["'False'","'False'","'False'","'False'","'False'","'True'","'True'","'True'","'True'","'True'"];
$Q1=switch($k1, $a,$b,$c,$d,$e,$f,$g,$h,$i,$j);
$A1=switch($k1, $Answers);
$D1=switch($k1, $Distractors);
$Q2=switch($k2, $a,$b,$c,$d,$e,$f,$g,$h,$i,$j);
$A2=switch($k2, $Answers);
$D2=switch($k2, $Distractors);
$Q3=switch($k3, $a,$b,$c,$d,$e,$f,$g,$h,$i,$j);
$A3=switch($k3, $Answers);
$D3=switch($k3, $Distractors);
$Q4=switch($k4, $a,$b,$c,$d,$e,$f,$g,$h,$i,$j);
$A4=switch($k4, $Answers);
$D4=switch($k4, $Distractors);
$Q5=switch($k5, $a,$b,$c,$d,$e,$f,$g,$h,$i,$j);
$A5=switch($k5, $Answers);
$D5=switch($k5, $Distractors);@
qu.1.17.uid=7c9e359c-a7ce-48c7-8022-0a0304839996@
qu.1.17.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Easy;
  Features=None;
  Type=Concept;
@
qu.1.17.weighting=1,1,1,1,1@
qu.1.17.numbering=alpha@
qu.1.17.part.1.grader=exact@
qu.1.17.part.1.name=sro_id_1@
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qu.1.17.part.1.mode=List@
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qu.1.17.part.2.display.permute=true@
qu.1.17.part.2.question=(Unset)@
qu.1.17.part.2.answer.2=$D2@
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qu.1.17.part.3.grader=exact@
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qu.1.17.part.3.display.permute=true@
qu.1.17.part.3.question=(Unset)@
qu.1.17.part.3.answer.2=$D3@
qu.1.17.part.3.answer.1=$A3@
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qu.1.17.part.4.name=sro_id_4@
qu.1.17.part.4.editing=useHTML@
qu.1.17.part.4.display.permute=true@
qu.1.17.part.4.question=(Unset)@
qu.1.17.part.4.answer.2=$D4@
qu.1.17.part.4.answer.1=$A4@
qu.1.17.part.4.mode=List@
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qu.1.17.part.4.credit.2=0.0@
qu.1.17.part.4.credit.1=1.0@
qu.1.17.part.5.grader=exact@
qu.1.17.part.5.name=sro_id_5@
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qu.1.17.part.5.display.permute=true@
qu.1.17.part.5.question=(Unset)@
qu.1.17.part.5.answer.2=$D5@
qu.1.17.part.5.answer.1=$A5@
qu.1.17.part.5.mode=List@
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qu.1.17.question=<p>Identify each of the following statements as either TRUE or FALSE.</p><p>&nbsp;</p><p>a)&nbsp;<span>&nbsp;</span><1><span>&nbsp;</span> $Q1</p><p>&nbsp;</p><p>b)&nbsp;<span>&nbsp;</span><2><span>&nbsp;</span> $Q2</p><p>&nbsp;</p><p>c)&nbsp;<span>&nbsp;</span><3><span>&nbsp;</span> $Q3</p><p>&nbsp;</p><p>d)&nbsp;<span>&nbsp;</span><4><span>&nbsp; $Q4</span></p><p>&nbsp;</p><p><span>e)&nbsp;<span>&nbsp;</span><5><span>&nbsp;</span> $Q5</span></p>@

qu.1.18.mode=Matching@
qu.1.18.name=Veterinarian Study; Match: Population, Parameter, Sample, Statistics@
qu.1.18.comment=<p>A&nbsp;<em>population</em> is the set of all experimental units of interest to the researcher; here, it is the 50 dogs on the low-calorie diet.</p>
<p>A <em>sample</em> is a subset of the population, which in this case is the 10 dogs the veterinarian randomly selected.</p>
<p>A <em>parameter</em> is a characteristic of the population.&nbsp; Since the population is the 50 dogs, the parameter is the mean weight of these 50 dogs, which is 2.1 kg.</p>
<p>A <em>statistic</em> is a characteristic of the sample.&nbsp; Since the sample consisted of 10 randomly selected dogs on the low-calorie diet, the statistic is the mean weight of the dogs in the sample, which is 1.7 kg.</p>@
qu.1.18.editing=useHTML@
qu.1.18.solution=@
qu.1.18.algorithm=@
qu.1.18.uid=c7866e1c-a776-44dd-a0d2-15a0155e98b5@
qu.1.18.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Easy;
  Features=None;
  Type=Concept;
@
qu.1.18.format.columns=4@
qu.1.18.question=<p>A veterinarian is interested in determining the average weight loss in dogs when placed on a new low-calorie diet.&nbsp;&nbsp;She takes a random sample of 10&nbsp;dogs&nbsp;out of the 50 dogs in her clinic that are on this special&nbsp;diet, and determines that their average weight loss is about 1.7 kg.&nbsp; Unbeknownst to her, the average weight loss for all the dogs on this diet is actually 2.1 kg.&nbsp;</p>
<p>&nbsp;</p>
<p>Match each of the numbered items in the list with the numbers in the drop-down menus:</p>@
qu.1.18.term.1=Parameter@
qu.1.18.term.1.def.1=2.1 kg@
qu.1.18.term.2=Statistic@
qu.1.18.term.2.def.1=1.7 kg@
qu.1.18.term.3=Population@
qu.1.18.term.3.def.1=50 dogs@
qu.1.18.term.4=Sample@
qu.1.18.term.4.def.1=10 dogs@

qu.1.19.mode=True False@
qu.1.19.name=Probability of selection in a simple random sample@
qu.1.19.comment=<p><em>TRUE</em></p>
<p>Assuming the population is large, say of size <em>N</em>, then the probability for any single individual to be selected for the sample in simple random sampling is <math xmlns='http://www.w3.org/1998/Math/MathML'><mstyle fontfamily='Times New Roman' mathsize='12' mathcolor='#000000' veryverythinmathspace='0.0555556em' verythinmathspace='0.111111em' thinmathspace='0.166667em' mediummathspace='0.222222em' thickmathspace='0.277778em' verythickmathspace='0.333333em' veryverythickmathspace='0.388889em' scriptlevel='0' scriptsizemultiplier='0.71' scriptminsize='8.0pt'><mrow><mfrac><mn>1</mn><mrow><mi>N</mi></mrow></mfrac></mrow></mstyle></math>, which will be the same for all individuals in the population.</p>@
qu.1.19.editing=useHTML@
qu.1.19.solution=@
qu.1.19.algorithm=@
qu.1.19.uid=0e9adee5-ad99-4b32-9134-e893431a0799@
qu.1.19.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Easy;
  Features=None;
@
qu.1.19.question=<p>Assuming a large population, in simple random sampling each individual in the population has the same probability of being selected.</p>@
qu.1.19.answer=1@
qu.1.19.choice.1=True@
qu.1.19.choice.2=False@
qu.1.19.fixed=@

qu.1.20.mode=True False@
qu.1.20.name=Bias in sampling methods@
qu.1.20.comment=<p><em>FALSE</em>.</p>
<p>Strong biases may be present in many different sampling methods, with some methods being more susceptible to bias than others.</p>@
qu.1.20.editing=useHTML@
qu.1.20.solution=@
qu.1.20.algorithm=@
qu.1.20.uid=86f34477-c369-44c3-8f8c-a24563eb9b05@
qu.1.20.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Easy;
  Features=None;
@
qu.1.20.question=<p>Sampling methods other than simple random sampling are always free of strong biases.</p>@
qu.1.20.answer=2@
qu.1.20.choice.1=True@
qu.1.20.choice.2=False@
qu.1.20.fixed=@

qu.1.21.mode=True False@
qu.1.21.name=Showing causation between explanatory and response variables@
qu.1.21.comment=<p><em>TRUE</em>.</p>
<p>In order to show <em>causation</em> between the explanatory variable and the response variable, other (i.e. lurking) variables need to be accounted for, which can be done in a well-designed experiment.</p>@
qu.1.21.editing=useHTML@
qu.1.21.solution=@
qu.1.21.algorithm=@
qu.1.21.uid=ba64e60b-b5af-4741-be6b-0fe925bda07e@
qu.1.21.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Easy;
  Features=None;
@
qu.1.21.question=<p>In a well-designed experiment, it may be possible to show a <em>causal</em> relationship between the explanatory variable and the response variable.</p>@
qu.1.21.answer=1@
qu.1.21.choice.1=True@
qu.1.21.choice.2=False@
qu.1.21.fixed=@

qu.1.22.mode=Multiple Selection@
qu.1.22.name=Definitions 2: Sampling methods and Variables@
qu.1.22.comment=@
qu.1.22.editing=useHTML@
qu.1.22.solution=@
qu.1.22.algorithm=@
qu.1.22.uid=dcccbbeb-b250-4701-bfbf-46037fbf2754@
qu.1.22.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Features=None;
  Difficulty=Easy;
  Type=Concept;
@
qu.1.22.question=<p>Which of the following statements are true?</p>
<p>&nbsp;</p>
<p>Note that there may be more than one correct answer; select all that are true.</p>@
qu.1.22.answer=1, 2, 3@
qu.1.22.choice.1=One advantage of stratified random sampling is to ensure that each strata gets adequate representation in the sample.@
qu.1.22.choice.2=A response variable is the outcome of the experiment or study.@
qu.1.22.choice.3=In a well-designed experiment, it may be possible to show a causal relationship between the explanatory variable and the response variable.@
qu.1.22.choice.4=In an experiment, researchers do not impose any conditions on the experimental units.@
qu.1.22.choice.5=Sampling methods other than simple random sampling are always free of strong biases.@
qu.1.22.fixed=@

qu.1.23.mode=Inline@
qu.1.23.name=Soccer Coach Study; Select Experiment, Observational or Survey@
qu.1.23.comment=<p>This type of study is an <em>observational study</em>, as the&nbsp;soccer coach simply observed the explanatory and response variables, and did no&nbsp;imposed conditions on the experimental units.</p>@
qu.1.23.editing=useHTML@
qu.1.23.solution=@
qu.1.23.algorithm=@
qu.1.23.uid=83956c51-7422-40a5-9b3e-cb737ddd9652@
qu.1.23.info=  Course=Introductory Statistics;
  Topic=Introduction to Statistics;
  Author=Lorna Deeth;
  Difficulty=Easy;
  Features=None;
  Type=Concept;
@
qu.1.23.weighting=1@
qu.1.23.numbering=alpha@
qu.1.23.part.1.grader=exact@
qu.1.23.part.1.name=sro_id_1@
qu.1.23.part.1.editing=useHTML@
qu.1.23.part.1.display.permute=true@
qu.1.23.part.1.answer.3=Survey@
qu.1.23.part.1.question=(Unset)@
qu.1.23.part.1.answer.2=Observational Study@
qu.1.23.part.1.answer.1=Experiment@
qu.1.23.part.1.mode=List@
qu.1.23.part.1.display=menu@
qu.1.23.part.1.credit.3=0.0@
qu.1.23.part.1.credit.2=1.0@
qu.1.23.part.1.credit.1=0.0@
qu.1.23.question=<p>A coach for a junior boys soccer team is interested in determining if there is a relationship between a player's activity level at home, and his stamina on the soccer field.&nbsp; For one week, the coach asks each of his players to report on&nbsp;their daily activities at home, then records how long it&nbsp;takes&nbsp;each play to run 5 laps of the soccer field.</p><p>&nbsp;</p><p>This type of study could best be described as a:&nbsp;<span>&nbsp;</span><1><span>&nbsp;</span></p>@

