STAT 121 Exam need to Study Questions
Verified Answers
What is a definition ? - ANS a types of observational study in which individuals report variables'
values themselves, frequently by giving their opinions
What is purpose? - ANS sample fact in place of population fact (take what know about
the sample and determine the population)
What is the population in the potato example?
a) all potatoes in the world
b) all potatoes in the U.S.
c) all potatoes in the truckload
d) all potatoes in the buckets - ANS c) all potatoes in the truckload
What is the variable? - ANS characteristic that is measured
Parameter is related to what piece of information? What is statistic related to? - ANS Parameter
- population
Statistic - sample
What is the sampling method where you break the population into groups and get the sample
from each group (not randomized)? - ANS Quota Sampling
`
,What are the 3 bad ways of sampling? - ANS Quota sampling
Volunteer response sampling
Convenience sampling
To participate in the time.com poll go to the time website and click. What kind of sample is
time.com poll?
a) convenience
b) volunteer response
c) quota - ANS b) volunteer response
What is SRS? - ANS Simple Random Sample
What is the definition of SRS? - ANS Sample of specified size chosen such that every possible set
of that size has equal chance of being the sample
What is stratified random sampling? - ANS Quota samplind done right, because once you select
different groups, you randomize the samples in each group
What is a multistage sample? - ANS 1) SRS sample of state
2) SRS sample of counties in state
3) SRS farms in county
4) combined => 1 sample
The IRS obtains a sample of Utah tax returns by taking a random sample of Utah counties and
then taking a random sample of returns filed in those counties. What kind of sample is this?
a) SRS
b) Stratified random sample
c) multistage sample
,d) cluster sample - ANS c) multistage sample
Which is better?
a) random sample of size 400
b) a nonrandom sample of size 5000 - ANS a) random sample of size 400
What is an experiment? - ANS you impose a condition on subjects
CAN determine cause/effect
What is an explanatory variable? - ANS used to predict or explain changes int he
response variable
What are lurking variables? - ANS variables that affect response variable but no measures
or included in planned factors (i.e. age, diet, emotional support, gender, etc.)
What is an observational study? - ANS -subjects choose treatment
-subjects naturally on treatment (previous to study) -passive data
collection
CANNOT have cause/effect relationship
What is a response variable? - ANS characteristic measured on each subject
What is a subject? - ANS individual to which treatment applied
What is treatment? - ANS
What are the possible biases? - ANS under coverage
non-responsive
, interviewer effect
question wording
question order
misleading response
What is under coverage? - ANS some people have no possibility of being selected
What is non-responsive? - ANS people refuse to answer/cannot be contacted
What is interviewer effect? - ANS interviewer influences responses (i.e. rude,
intimidating, subtle clues, gestures)
What is question wording? - ANS wording of questions leads, mislead, or confuses
What is misleading response? - ANS individuals lie or give inaccurate responses
what is an example of a misleading response? - ANS sensitive issues
An automobile salesman tells you that he gets a bonus if you report on a post-sale survey that
he was effective and courteous. What kind of bias might be present in this survey?
a. nonresponse
b. undercoverage
c. misleading response
d. no bias - ANS c. misleading response
What is question ordering in regards to collecting statistical data? - ANS way questions
ordered affects responses
Verified Answers
What is a definition ? - ANS a types of observational study in which individuals report variables'
values themselves, frequently by giving their opinions
What is purpose? - ANS sample fact in place of population fact (take what know about
the sample and determine the population)
What is the population in the potato example?
a) all potatoes in the world
b) all potatoes in the U.S.
c) all potatoes in the truckload
d) all potatoes in the buckets - ANS c) all potatoes in the truckload
What is the variable? - ANS characteristic that is measured
Parameter is related to what piece of information? What is statistic related to? - ANS Parameter
- population
Statistic - sample
What is the sampling method where you break the population into groups and get the sample
from each group (not randomized)? - ANS Quota Sampling
`
,What are the 3 bad ways of sampling? - ANS Quota sampling
Volunteer response sampling
Convenience sampling
To participate in the time.com poll go to the time website and click. What kind of sample is
time.com poll?
a) convenience
b) volunteer response
c) quota - ANS b) volunteer response
What is SRS? - ANS Simple Random Sample
What is the definition of SRS? - ANS Sample of specified size chosen such that every possible set
of that size has equal chance of being the sample
What is stratified random sampling? - ANS Quota samplind done right, because once you select
different groups, you randomize the samples in each group
What is a multistage sample? - ANS 1) SRS sample of state
2) SRS sample of counties in state
3) SRS farms in county
4) combined => 1 sample
The IRS obtains a sample of Utah tax returns by taking a random sample of Utah counties and
then taking a random sample of returns filed in those counties. What kind of sample is this?
a) SRS
b) Stratified random sample
c) multistage sample
,d) cluster sample - ANS c) multistage sample
Which is better?
a) random sample of size 400
b) a nonrandom sample of size 5000 - ANS a) random sample of size 400
What is an experiment? - ANS you impose a condition on subjects
CAN determine cause/effect
What is an explanatory variable? - ANS used to predict or explain changes int he
response variable
What are lurking variables? - ANS variables that affect response variable but no measures
or included in planned factors (i.e. age, diet, emotional support, gender, etc.)
What is an observational study? - ANS -subjects choose treatment
-subjects naturally on treatment (previous to study) -passive data
collection
CANNOT have cause/effect relationship
What is a response variable? - ANS characteristic measured on each subject
What is a subject? - ANS individual to which treatment applied
What is treatment? - ANS
What are the possible biases? - ANS under coverage
non-responsive
, interviewer effect
question wording
question order
misleading response
What is under coverage? - ANS some people have no possibility of being selected
What is non-responsive? - ANS people refuse to answer/cannot be contacted
What is interviewer effect? - ANS interviewer influences responses (i.e. rude,
intimidating, subtle clues, gestures)
What is question wording? - ANS wording of questions leads, mislead, or confuses
What is misleading response? - ANS individuals lie or give inaccurate responses
what is an example of a misleading response? - ANS sensitive issues
An automobile salesman tells you that he gets a bonus if you report on a post-sale survey that
he was effective and courteous. What kind of bias might be present in this survey?
a. nonresponse
b. undercoverage
c. misleading response
d. no bias - ANS c. misleading response
What is question ordering in regards to collecting statistical data? - ANS way questions
ordered affects responses
