ST 511 Midterm questions well
answered graded A+
A local corporation was interested in the purchasing habits of Wake County residents.
Specifically one of the things they were interested in was the proportions of residents that did a
major home improvement project in the last year. The corporation used a list of all households
to take a simple random sample of households. The researcher then visited each of the sampled
homes and found that 21 of 100 homes had completed a major home improvement project.
Which of the following are true? - ANS ✔✔The parameter of interest is the proportion of
residents that did a major home improvement project in the last year.
The population of interest is the 100 homes that were sampled.
The researcher will compile an alphabetical list of all high school mathematics teachers in the
state. She will divide the list into those with last name starting with the letters A through K and
those with last names starting with L-Z. She will number these two lists and use a random
number generator to pick 50 from the A-K list and 50 from the L-Z list. - ANS ✔✔stratified
The researcher will compile a list of all high school mathematics teachers in the state. She will
number this list and use a random number generator to pick 100 teachers. - ANS ✔✔SRS
the researcher creates a website that has the survey on it. She then sends a poster to all high
schools in the state asking mathematics teachers to go online and fill out the survey. - ANS
✔✔volunteer response
The researcher will compile a list of all high school mathematics teachers in the state. She will
divide the list into NBC teachers and non-NBC teachers. She will number these two lists and use
a random number generator to pick 50 NBC teachers and 50 non-NBC teachers. - ANS
✔✔stratified
, The researcher will randomly select 25 high schools from a list of all high schools in the state.
She then goes to each high school and talks with all the mathematics teachers at those high
schools. - ANS ✔✔cluster
The researcher from DPI will go to the 10 closest high schools to the DPI central office. At each
high school she will talk with all the mathematics teachers at that location. - ANS
✔✔convenience
DPI collects data from many schools, where each teacher was able to determine for themselves
which teaching method they used. - ANS ✔✔observational study
DPI randomly assigns half of the teachers within a specific school to use the new method for all
of their classes and the other half in the same school to use the standard method for all of their
classes. DPI repeats this process for several schools. - ANS ✔✔block design
DPI tells teachers to use the new method for half of their classes and the standard method for
the other half of their classes, randomly assigning which class gets which method - ANS
✔✔matched pairs design
DPI randomly assigns some teachers to use the new method for all of their classes and other
teachers to use the standard method for all of their classes. - ANS ✔✔completely randomized
DPI randomly assigns all teachers in some schools to use the new method for all of their classes
and all teachers in other schools to use the standard method for all of their classes. - ANS
✔✔completely randomized
A professor wanted to determine the proportion of students in his class who have cheated on
an exam. The professor selects a random sample of 30 students from his class and emails them
the question "Have you ever cheated on an exam?". He receives responses from 10 of the 30
students. Which of the following statements are true? - ANS ✔✔this study suffers from non-
response bias because only 33% of the people surveyed provided a response.
answered graded A+
A local corporation was interested in the purchasing habits of Wake County residents.
Specifically one of the things they were interested in was the proportions of residents that did a
major home improvement project in the last year. The corporation used a list of all households
to take a simple random sample of households. The researcher then visited each of the sampled
homes and found that 21 of 100 homes had completed a major home improvement project.
Which of the following are true? - ANS ✔✔The parameter of interest is the proportion of
residents that did a major home improvement project in the last year.
The population of interest is the 100 homes that were sampled.
The researcher will compile an alphabetical list of all high school mathematics teachers in the
state. She will divide the list into those with last name starting with the letters A through K and
those with last names starting with L-Z. She will number these two lists and use a random
number generator to pick 50 from the A-K list and 50 from the L-Z list. - ANS ✔✔stratified
The researcher will compile a list of all high school mathematics teachers in the state. She will
number this list and use a random number generator to pick 100 teachers. - ANS ✔✔SRS
the researcher creates a website that has the survey on it. She then sends a poster to all high
schools in the state asking mathematics teachers to go online and fill out the survey. - ANS
✔✔volunteer response
The researcher will compile a list of all high school mathematics teachers in the state. She will
divide the list into NBC teachers and non-NBC teachers. She will number these two lists and use
a random number generator to pick 50 NBC teachers and 50 non-NBC teachers. - ANS
✔✔stratified
, The researcher will randomly select 25 high schools from a list of all high schools in the state.
She then goes to each high school and talks with all the mathematics teachers at those high
schools. - ANS ✔✔cluster
The researcher from DPI will go to the 10 closest high schools to the DPI central office. At each
high school she will talk with all the mathematics teachers at that location. - ANS
✔✔convenience
DPI collects data from many schools, where each teacher was able to determine for themselves
which teaching method they used. - ANS ✔✔observational study
DPI randomly assigns half of the teachers within a specific school to use the new method for all
of their classes and the other half in the same school to use the standard method for all of their
classes. DPI repeats this process for several schools. - ANS ✔✔block design
DPI tells teachers to use the new method for half of their classes and the standard method for
the other half of their classes, randomly assigning which class gets which method - ANS
✔✔matched pairs design
DPI randomly assigns some teachers to use the new method for all of their classes and other
teachers to use the standard method for all of their classes. - ANS ✔✔completely randomized
DPI randomly assigns all teachers in some schools to use the new method for all of their classes
and all teachers in other schools to use the standard method for all of their classes. - ANS
✔✔completely randomized
A professor wanted to determine the proportion of students in his class who have cheated on
an exam. The professor selects a random sample of 30 students from his class and emails them
the question "Have you ever cheated on an exam?". He receives responses from 10 of the 30
students. Which of the following statements are true? - ANS ✔✔this study suffers from non-
response bias because only 33% of the people surveyed provided a response.
