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STT 200 exam 1 Questions and Answers (100%
Correct Answers) Already Graded A+
the placebo effect Ans: treatment that gives no physiological effect
single blind study Ans: no one in the experiment except the researchers
and evaluators know the treatment condition
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double blind study Ans: no one in the experiment group knows the
treatment condition
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confounding factor Ans: when the treatment and control group differ in
some respect other than the treatment
anecdotal evidence Ans: composed of unusual cases that are recalled
based on their striking characteristics
simple random sampling (SRS) Ans: each possible sample of that size has
the same probability of selection
cluster sampling Ans: randomly sample some clusters, then observe all
the elements in the chosen cluster
systematic sampling Ans: randomly select a fixed starting point and then
select every Kth person in the population (K is the population size divided
by the desired sample size)
convenience sampling Ans: obtained by measuring whatever or
whoever is available to be measured
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selected bias Ans: occurs if the method for selecting the participants
produces a sample that does not represent the population of interest
nonresponse bias Ans: when a representative sample is chosen for a
survey, but a subset cannot be contacted or does not respond, the
subset differs in a meaningful way
responce bias Ans: occurs when participants respond differently from
how they truly feel
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categorical varibles Ans: classifies cases into groups or categories,
placing each case into exactly one or two or more categories
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numerical varible Ans: measure or record a numerical quantity for each
case
nominal Ans: has categories that do not have a natural order
ordinal Ans: categories whose levels have some logical ordering
numerical Ans: different subtypes, numerical values
mosaic plots Ans: use area to represent the number of observations in a
given cell of a two way table
symmetric and bell shaped Ans: date is clustered in the middle with an
right skewed Ans: most data have smaller values, with just a few larger
values