STAT Exam 1 Assignment Review
Use the information below to answer the questions that follow: - answer Via telephone
interviews conducted during a four-day span, Gallup polled a random sample of 1,032
adults (age 18+) from all 50 U.S. states and the District of Columbia. 19% indicated that
they approve of the way that Congress is handling its job.
What is the population of interest for the Gallup poll? - answerAll US adults
Among the options, the sample would best represent all US adults.
What is the sample? - answer1,032 US adults
The sample is the 1,032 US adults who were polled
Which of the following was the question most likely posed by Gallup in conducting the
survey? - answer"Do you approve or disapprove of the way Congress is handling its
job?"
Among the options, "Do you approve or disapprove of the way Congress is handling its
job?" would be the best option. Not leading the respondent toward a particular response
and not unnecessarily complex.
What type of data was collected with this particular poll question? - answerCategorical
What type of study is this? - answerObservational Study
This is an observational study, because the opinions of the respondents are simply
observed.
If respondents had also been asked to indicate the length of time that a member of
Congress should be able to serve before being forced to retire, what type of data would
that be? - answerMeasurement Continuous
Length of time would be a measurement continuous variable.
Use the information below to answer the following questions: - answerAn educator
wants to compare the effectiveness of computer software that teaches reading against a
standard reading curriculum. The educator tests the reading ability of a group of 60
students - who were volunteered by their parents - and then randomly assigns them into
classes of 30 students each. One class uses the computer software regularly while the
other class does not. At the end, the educator retests the students to determine their
,change in reading ability score. Then the researcher compares the average change in
reading ability scores for the two groups of students.
Which of the following statements is accurate as it relates to the type of comparative
study described above? - answerThis is an experiment because the students were
randomly assigned to the two different reading curricula.
The type of reading curricula was randomly assigned to the units (i.e. students).
"Change in reading ability score" (i.e. post-score minus pre-score) is what type of
variable? - answerMeasurement
This is a numeric score (notice that the "change" is found by subtracting), so it is a
measurement variable.
Why would a sample of 100 students be preferred over a sample of 60 students with
this study? - answerThe increase in sample size would make it easier to detect a
difference between the two reading curricula, if one actually exists.
Using a convenience sample is an effective way to ensure a representative sample.
You Answered True - answerFalse
The larger the variation in the measurements within two groups, the smaller the sample
size necessary to detect a difference between those two groups. - answerFalse
In order to make a causal conclusion in a statistical study, the participants must be
randomly assigned to the groups that will be compared in the study. - answerTrue
An open-ended pilot survey can be utilized to determine the most appropriate answer
options for a closed form of the same survey. - answerTrue
Consider these survey questions:
"Do you support banning prayer in schools?"
"Do you support not allowing prayer in schools?"
Based on the concepts covered in this lesson, which question will garner a higher
percentage of support (i.e. a higher percentage of respondents who say "Yes")? -
answerThe percentage of agreement should be higher for the second question.
The percentage of agreement should be higher for the second question because the
wording ("not allowing" vs "banning") is not as strong. Some respondents will not agree
with the first question simply because of the intensity of the word "banning."
The owner of a company asks each of her employees, "Do you agree or disagree that I
am an effective leader of this company?" She does so in face-to-face conversations.
Which is most likely to impact the outcome of her "poll"? - answerDesire to please
, Giving personal feedback face-to-face will certainly be impacted by a desire to please.
"Don't you think that Donald Trump is an illegitimate president because of the Russian
influence on the election?" This question demonstrates which of the following pitfalls? -
answerDeliberate bias and Unnecessary complexity
The beginning of the question ("Don't you think...") points the person in one direction.
The question is also unnecessary complex, giving one specific reason that may
question the legitimacy of Trump's presidency. Someone may think that he is not a
legitimate president, but not necessarily for the stated reason. This will cause confusion
as to how the person should answer the question.
A scale that consistently indicates objects are 2 lbs heavier than they really are would
be considered __________. - answerBiased
The issue here is that the scale is always 2 lbs off of the true weight, so it is biased. The
scale is measuring weight (valid) and is doing so reliably (consistent results), but it is
always incorrect by the same amount of weight and in the same direction.
The primary issue with obtaining weight data on a group of college students by
measuring their height would be a(n) ____________ measure. - answerInvalid
It is quite possible for height to be measured without bias and with reliability, but it is not
a valid measure of weight. It does not measure (height) what is intended to be
measured (weight).
At the local mall, two stores, a department store and a boutique, sell coats. During the
past holiday season, the department store sold 1000 coats while the boutique sold 100
coats. Thirty-six coats were returned to the department store while only 10 coats were
returned to the boutique. - answerpercent of coats returned
The percent of coats returned is most valid because it incorporates the sales
information. The numbers of coats returned for the two stores imply that the department
store has the bigger "return issue," but when the sales volume is incorporated, it is
obvious that the RATE of return for the department store is much lower than that for the
boutique.
Which of the following is NOT an important aspect of conducting a statistical study
properly? - answerHaving an advanced degree in statistics
A statistical study can be done properly without an advanced degree in statistics. All the
other options are important aspects of a proper study.
Which of the following characteristics of a car is a categorical variable? - answercolor of
car's exterior
Use the information below to answer the questions that follow: - answer Via telephone
interviews conducted during a four-day span, Gallup polled a random sample of 1,032
adults (age 18+) from all 50 U.S. states and the District of Columbia. 19% indicated that
they approve of the way that Congress is handling its job.
What is the population of interest for the Gallup poll? - answerAll US adults
Among the options, the sample would best represent all US adults.
What is the sample? - answer1,032 US adults
The sample is the 1,032 US adults who were polled
Which of the following was the question most likely posed by Gallup in conducting the
survey? - answer"Do you approve or disapprove of the way Congress is handling its
job?"
Among the options, "Do you approve or disapprove of the way Congress is handling its
job?" would be the best option. Not leading the respondent toward a particular response
and not unnecessarily complex.
What type of data was collected with this particular poll question? - answerCategorical
What type of study is this? - answerObservational Study
This is an observational study, because the opinions of the respondents are simply
observed.
If respondents had also been asked to indicate the length of time that a member of
Congress should be able to serve before being forced to retire, what type of data would
that be? - answerMeasurement Continuous
Length of time would be a measurement continuous variable.
Use the information below to answer the following questions: - answerAn educator
wants to compare the effectiveness of computer software that teaches reading against a
standard reading curriculum. The educator tests the reading ability of a group of 60
students - who were volunteered by their parents - and then randomly assigns them into
classes of 30 students each. One class uses the computer software regularly while the
other class does not. At the end, the educator retests the students to determine their
,change in reading ability score. Then the researcher compares the average change in
reading ability scores for the two groups of students.
Which of the following statements is accurate as it relates to the type of comparative
study described above? - answerThis is an experiment because the students were
randomly assigned to the two different reading curricula.
The type of reading curricula was randomly assigned to the units (i.e. students).
"Change in reading ability score" (i.e. post-score minus pre-score) is what type of
variable? - answerMeasurement
This is a numeric score (notice that the "change" is found by subtracting), so it is a
measurement variable.
Why would a sample of 100 students be preferred over a sample of 60 students with
this study? - answerThe increase in sample size would make it easier to detect a
difference between the two reading curricula, if one actually exists.
Using a convenience sample is an effective way to ensure a representative sample.
You Answered True - answerFalse
The larger the variation in the measurements within two groups, the smaller the sample
size necessary to detect a difference between those two groups. - answerFalse
In order to make a causal conclusion in a statistical study, the participants must be
randomly assigned to the groups that will be compared in the study. - answerTrue
An open-ended pilot survey can be utilized to determine the most appropriate answer
options for a closed form of the same survey. - answerTrue
Consider these survey questions:
"Do you support banning prayer in schools?"
"Do you support not allowing prayer in schools?"
Based on the concepts covered in this lesson, which question will garner a higher
percentage of support (i.e. a higher percentage of respondents who say "Yes")? -
answerThe percentage of agreement should be higher for the second question.
The percentage of agreement should be higher for the second question because the
wording ("not allowing" vs "banning") is not as strong. Some respondents will not agree
with the first question simply because of the intensity of the word "banning."
The owner of a company asks each of her employees, "Do you agree or disagree that I
am an effective leader of this company?" She does so in face-to-face conversations.
Which is most likely to impact the outcome of her "poll"? - answerDesire to please
, Giving personal feedback face-to-face will certainly be impacted by a desire to please.
"Don't you think that Donald Trump is an illegitimate president because of the Russian
influence on the election?" This question demonstrates which of the following pitfalls? -
answerDeliberate bias and Unnecessary complexity
The beginning of the question ("Don't you think...") points the person in one direction.
The question is also unnecessary complex, giving one specific reason that may
question the legitimacy of Trump's presidency. Someone may think that he is not a
legitimate president, but not necessarily for the stated reason. This will cause confusion
as to how the person should answer the question.
A scale that consistently indicates objects are 2 lbs heavier than they really are would
be considered __________. - answerBiased
The issue here is that the scale is always 2 lbs off of the true weight, so it is biased. The
scale is measuring weight (valid) and is doing so reliably (consistent results), but it is
always incorrect by the same amount of weight and in the same direction.
The primary issue with obtaining weight data on a group of college students by
measuring their height would be a(n) ____________ measure. - answerInvalid
It is quite possible for height to be measured without bias and with reliability, but it is not
a valid measure of weight. It does not measure (height) what is intended to be
measured (weight).
At the local mall, two stores, a department store and a boutique, sell coats. During the
past holiday season, the department store sold 1000 coats while the boutique sold 100
coats. Thirty-six coats were returned to the department store while only 10 coats were
returned to the boutique. - answerpercent of coats returned
The percent of coats returned is most valid because it incorporates the sales
information. The numbers of coats returned for the two stores imply that the department
store has the bigger "return issue," but when the sales volume is incorporated, it is
obvious that the RATE of return for the department store is much lower than that for the
boutique.
Which of the following is NOT an important aspect of conducting a statistical study
properly? - answerHaving an advanced degree in statistics
A statistical study can be done properly without an advanced degree in statistics. All the
other options are important aspects of a proper study.
Which of the following characteristics of a car is a categorical variable? - answercolor of
car's exterior
