Introduction to Statistics Final (2025)
comprehensive questions and verified
detailed solutions
The sample is the 857 people who responded - 📌📌 - One year a survey asked
a group of people from a certain country the following question, "How many
foreign languages do you know?" Of the 857 people who responded, 66%
reported knowing only 1 foreign language. Identify the sample.
📌📌
The percentages quoted are statistics because they are a numerical summary of
a sample taken from a population - - A poll of about 1200 people between
the ages of 50 and 64 asked "How concerned are you about the problem of
natural disasters?" The possible responses were very concerned, somewhat
concerned, not very concerned, and haven't heard about it. The poll reported
percentages (44, 30, 22, 4) in these categories.
Are the percentages statistics or parameters?
Categorical - 📌📌
- Categorical or Quantitative?
Beverage preference
Qualitative -📌📌- Categorical or Quantitative?
Size of home
continuous - 📌📌- Continuous or discrete?
Height of a tree
discrete -📌📌 - Continuous or discrete?
Number of socks in a drawer
the fact that the mean is larger than the median for the group indicates that there
📌📌
are extremely large incomes that are affecting the mean, suggesting the shape is
skewed to the right. - - According to a study, the median household income
for a group was $50,043 while the mean was $73,409. Does this suggest that the
distribution of household income for the group is symmetric, skewed tot he right,
or skewed to the left?
📌📌
Grade received is the response variable because it is the outcome variable on
which comparisons are made and Effort is the explanatory variable. - - For
the following pair of variables, which more naturally is the response variable and
which is the explanatory variable?
, age of the car and the resale value. What would one expect to be the association
between the variables?
📌📌
The colleges that used metal detectors may have formerly had higher rates of
students carrying concealed weapons. - - A study compared colleges that
used metal detectors with colleges that did not, finding similar levels of students
carrying concealed weapons in each. State a potential lurking variable that could
affect the result of such a study.
📌📌
This illustrates response bias because the participants may have altered answers
based on what they thought to be socially acceptable. - - A political scientist
studied the effect of the race of the interviewer. Following a phone interview,
respondents were asked whether they thought the interviewer was black or white
all were actually black). Perceiving a white interviewer resulted in more
conservative opinions.
For example, 14% agreed that "American society is fair to everyone" when they
thought the interviewer was black, but 31% agreed to this statement when posed
by an interviewer that the respondent thought was white. Which type of bias does
this illustrate?
📌📌
A stratified sample because the population is divided into separate groups and
each group is randomly sampled. - - A researcher wants to compare
student loan debt for students who attend four-year public universities with those
who attend four-year private universities. She plans to take a random sample of
100 recent graduates of public universities and 100 recent graduates of private
universities. Which type of random sampling is utilized in her study?
interval - 📌📌- Determine the level of measurement:
Temperature (in degrees, Fahrenheit)
nominal - 📌📌- Determine the level of measurement:
Sports jersey number
ordinal - 📌📌- Determine the level of measurement:
letter grade
interval - 📌📌- Determine the level of measurement:
stat score
ratio - 📌📌- Determine the level of measurement:
height
nominal - 📌📌- Determine the level of measurement:
zip code
comprehensive questions and verified
detailed solutions
The sample is the 857 people who responded - 📌📌 - One year a survey asked
a group of people from a certain country the following question, "How many
foreign languages do you know?" Of the 857 people who responded, 66%
reported knowing only 1 foreign language. Identify the sample.
📌📌
The percentages quoted are statistics because they are a numerical summary of
a sample taken from a population - - A poll of about 1200 people between
the ages of 50 and 64 asked "How concerned are you about the problem of
natural disasters?" The possible responses were very concerned, somewhat
concerned, not very concerned, and haven't heard about it. The poll reported
percentages (44, 30, 22, 4) in these categories.
Are the percentages statistics or parameters?
Categorical - 📌📌
- Categorical or Quantitative?
Beverage preference
Qualitative -📌📌- Categorical or Quantitative?
Size of home
continuous - 📌📌- Continuous or discrete?
Height of a tree
discrete -📌📌 - Continuous or discrete?
Number of socks in a drawer
the fact that the mean is larger than the median for the group indicates that there
📌📌
are extremely large incomes that are affecting the mean, suggesting the shape is
skewed to the right. - - According to a study, the median household income
for a group was $50,043 while the mean was $73,409. Does this suggest that the
distribution of household income for the group is symmetric, skewed tot he right,
or skewed to the left?
📌📌
Grade received is the response variable because it is the outcome variable on
which comparisons are made and Effort is the explanatory variable. - - For
the following pair of variables, which more naturally is the response variable and
which is the explanatory variable?
, age of the car and the resale value. What would one expect to be the association
between the variables?
📌📌
The colleges that used metal detectors may have formerly had higher rates of
students carrying concealed weapons. - - A study compared colleges that
used metal detectors with colleges that did not, finding similar levels of students
carrying concealed weapons in each. State a potential lurking variable that could
affect the result of such a study.
📌📌
This illustrates response bias because the participants may have altered answers
based on what they thought to be socially acceptable. - - A political scientist
studied the effect of the race of the interviewer. Following a phone interview,
respondents were asked whether they thought the interviewer was black or white
all were actually black). Perceiving a white interviewer resulted in more
conservative opinions.
For example, 14% agreed that "American society is fair to everyone" when they
thought the interviewer was black, but 31% agreed to this statement when posed
by an interviewer that the respondent thought was white. Which type of bias does
this illustrate?
📌📌
A stratified sample because the population is divided into separate groups and
each group is randomly sampled. - - A researcher wants to compare
student loan debt for students who attend four-year public universities with those
who attend four-year private universities. She plans to take a random sample of
100 recent graduates of public universities and 100 recent graduates of private
universities. Which type of random sampling is utilized in her study?
interval - 📌📌- Determine the level of measurement:
Temperature (in degrees, Fahrenheit)
nominal - 📌📌- Determine the level of measurement:
Sports jersey number
ordinal - 📌📌- Determine the level of measurement:
letter grade
interval - 📌📌- Determine the level of measurement:
stat score
ratio - 📌📌- Determine the level of measurement:
height
nominal - 📌📌- Determine the level of measurement:
zip code
