IDS 270 PRACTICE EXAM || QUESTIONS AND ANSWERS.
a telephone survey research company is not able to get a woman to answer questions about local
traffic conditions because she is busy baking cookies correct answers nonresponse bias
a student polls his friends to get data regarding grades at his university and represents his
findings as being representative of all students at that university correct answers convient sample
a certain IDS 270 instructor does not answer questions about his drinking habits while an
undergraduate at the University of Michigan with complete accuracy correct answers response
bias
Nightline posts results from a call in poll indicating that 60%of callers are in favor of gun control
correct answers volentary response bias
a researcher wants to estimate costs of higher education. He first puts the entire set of colleges
into groups that are relatively similar: Private colleges, 4 year universities, community colleges,
etc. He then samples from each of these groups and gets the cost of attending the college from
the sample. correct answers stratified sampling
mean of 2, 4, 6, 8 correct answers 20/4=5
median of 2, 4, 6, 8 correct answers add the two middle numbers and divide by two. 10/2=5
standard deviation of 2, 4, 6, 8 correct answers (2-5)^2+(4-5)^2+(6-5)^2+(8-5)^2=20
20/3 (3 bc n-1)
square root of 20/3
Observational study correct answers observes individuals and measures variables of interest but
does not attempt to influence the responses
, experiment correct answers deliberately imposes some treatment on individuals to observe their
responses
confounding correct answers two variables (explanatory variables of lurking variables) are
counfouded when their effects on a response variable cannot be distinguished from each other
sample correct answers we can't afford to ask all the adults so we put the question to a _____
chosen to represent the entire adult population. type of observational study
simple random sample correct answers the size n consists of n individuals from the population
chosen in such a way that every set of n individuals has an equal chance to be in the sample
actually selected
probability sample correct answers a sample chosen by chance. we must know what samples are
possible and what chance or probability each possible sample has.
stratified random sample correct answers first divide the population into groups of similar
individuals , called strata. then choose serrate SRS in each stratum an combine these SRSs to
form the full sample.
Current population survey correct answers conducts interviews in about 55,000 households each
month.
multistage sample correct answers It would be too expensive and not practical to maintain a list
of all U.S. households from which to select an SRS. the current population survey therefore uses
a ____________
wording effects correct answers the wording of questions is the most important influence on the
answers given to a sample survey.
a telephone survey research company is not able to get a woman to answer questions about local
traffic conditions because she is busy baking cookies correct answers nonresponse bias
a student polls his friends to get data regarding grades at his university and represents his
findings as being representative of all students at that university correct answers convient sample
a certain IDS 270 instructor does not answer questions about his drinking habits while an
undergraduate at the University of Michigan with complete accuracy correct answers response
bias
Nightline posts results from a call in poll indicating that 60%of callers are in favor of gun control
correct answers volentary response bias
a researcher wants to estimate costs of higher education. He first puts the entire set of colleges
into groups that are relatively similar: Private colleges, 4 year universities, community colleges,
etc. He then samples from each of these groups and gets the cost of attending the college from
the sample. correct answers stratified sampling
mean of 2, 4, 6, 8 correct answers 20/4=5
median of 2, 4, 6, 8 correct answers add the two middle numbers and divide by two. 10/2=5
standard deviation of 2, 4, 6, 8 correct answers (2-5)^2+(4-5)^2+(6-5)^2+(8-5)^2=20
20/3 (3 bc n-1)
square root of 20/3
Observational study correct answers observes individuals and measures variables of interest but
does not attempt to influence the responses
, experiment correct answers deliberately imposes some treatment on individuals to observe their
responses
confounding correct answers two variables (explanatory variables of lurking variables) are
counfouded when their effects on a response variable cannot be distinguished from each other
sample correct answers we can't afford to ask all the adults so we put the question to a _____
chosen to represent the entire adult population. type of observational study
simple random sample correct answers the size n consists of n individuals from the population
chosen in such a way that every set of n individuals has an equal chance to be in the sample
actually selected
probability sample correct answers a sample chosen by chance. we must know what samples are
possible and what chance or probability each possible sample has.
stratified random sample correct answers first divide the population into groups of similar
individuals , called strata. then choose serrate SRS in each stratum an combine these SRSs to
form the full sample.
Current population survey correct answers conducts interviews in about 55,000 households each
month.
multistage sample correct answers It would be too expensive and not practical to maintain a list
of all U.S. households from which to select an SRS. the current population survey therefore uses
a ____________
wording effects correct answers the wording of questions is the most important influence on the
answers given to a sample survey.
