Statistics Questions with CORRECT Answers (Verified Update)
Q1: she uses random assignment for each of her five classes to decide what genre to play for the
week. she used country, jazz, hip-hop, classical, and rock. she quizzes each class that Friday
and checks the results. what variable was kept the same for all subjects, and why was it
important that it be kept the same? - she quizzed for each class that friday, it's important so
we know what type of music improved her quiz scores, or if she did at all. this reduces
confounding, thus making it easier to determine if a genre of music was the reason. A local
news agency conducted a survey abt unemployment by randomly dialing phone numbers
until it had gathered responses from 1000 adults in the state. In the survey, 19% of those
who responded said they werent currently employed. In reality, only 6% of the adults in the
state were not employed at the time of the survey. which best explains the difference
between the two percentages?
A. it is due to sampling variability, we shouldn't expect the results of a random sample to
match the truth about the population every time.
B. the difference is due to response bias. adults who are employed are likely to lie and say
that they are unemployed.
C. The difference is due to under coverage. The survey included only adults and did not
include teenagers who are eligible to work.
D. the difference is due to nonresponse. Adults who are employed are less likely to be
available for the sample than adults who are unemployed. - D!! The difference is due to
NONRESPONSE. Adults who are employed are less likely to be available for the sample than
adults who are unemployed.
Answer: A. it is due to sampling variability, we shouldn't expect the results of a random sample to
match the truth about the population every time.
Q2: Some studies of the relationship between car color and frequency of accidents have found
that red cars are more likely to be in accidents than black cars, despite how visible they are.
Some experts warn that we should not conclude red cars are less safe than black cars
because of possible confounding. Which of the following best describes what this means?
A. There are too many variables involved in traffic accidents to isolate the effect of car color.
B. The accidents used in the study might not be a random sample of all accidents.
C. It is not possible to separate the effect of car color from the type of people who choose to
drive red cars.
D. It can be hard to determine if red cars or black cars are more visible on modern highways.
Answer: C. It is not possible to separate the effect of car color from the type of people who choose
to drive red cars.
, Q3: the following best describes what this means?
A. There are too many variables involved in traffic accidents to isolate the effect of car color.
B. The accidents used in the study might not be a random sample of all accidents.
C. It is not possible to separate the effect of car color from the type of people who choose to
drive red cars.
D. It can be hard to determine if red cars or black cars are more visible on modern highways.
Answer: C. It is not possible to separate the effect of car color from the type of people who choose
to drive red cars.
Q4: A new headache remedy was given to a group of 25 subjects who had headaches. Four hours
after taking the new remedy, 20 of the subjects reported that their headaches had
disappeared. From this information, you conclude
A. that the remedy is effective for the treatment of headaches.
B. nothing because the sample size is too small
C. nothing because there is no control group for comparison.
D. that the new treatment is better than aspirin.
Answer: C. nothing because there is no control group for comparison.
Q5: A gardener wants to try different combinations of fertilizer (none, 1 cup, 2 cups) and mulch
(none, wood chips, pine needles, plastic) to determine which combination produces the
highest yield for a variety of green beans. He has 60 green-bean plants to use in the
experiment. If he wants an equal number of plants to be assigned to each treatment, how
many plants will be assigned to each treatment?
A. 1
B. 3
C. 4
D. 5
Answer: D. 5
Q6: plants to be assigned to each treatment, how many plants will be assigned to each
treatment?
A. 1
B. 3
C. 4
D. 5
Answer: D. 5
Q1: she uses random assignment for each of her five classes to decide what genre to play for the
week. she used country, jazz, hip-hop, classical, and rock. she quizzes each class that Friday
and checks the results. what variable was kept the same for all subjects, and why was it
important that it be kept the same? - she quizzed for each class that friday, it's important so
we know what type of music improved her quiz scores, or if she did at all. this reduces
confounding, thus making it easier to determine if a genre of music was the reason. A local
news agency conducted a survey abt unemployment by randomly dialing phone numbers
until it had gathered responses from 1000 adults in the state. In the survey, 19% of those
who responded said they werent currently employed. In reality, only 6% of the adults in the
state were not employed at the time of the survey. which best explains the difference
between the two percentages?
A. it is due to sampling variability, we shouldn't expect the results of a random sample to
match the truth about the population every time.
B. the difference is due to response bias. adults who are employed are likely to lie and say
that they are unemployed.
C. The difference is due to under coverage. The survey included only adults and did not
include teenagers who are eligible to work.
D. the difference is due to nonresponse. Adults who are employed are less likely to be
available for the sample than adults who are unemployed. - D!! The difference is due to
NONRESPONSE. Adults who are employed are less likely to be available for the sample than
adults who are unemployed.
Answer: A. it is due to sampling variability, we shouldn't expect the results of a random sample to
match the truth about the population every time.
Q2: Some studies of the relationship between car color and frequency of accidents have found
that red cars are more likely to be in accidents than black cars, despite how visible they are.
Some experts warn that we should not conclude red cars are less safe than black cars
because of possible confounding. Which of the following best describes what this means?
A. There are too many variables involved in traffic accidents to isolate the effect of car color.
B. The accidents used in the study might not be a random sample of all accidents.
C. It is not possible to separate the effect of car color from the type of people who choose to
drive red cars.
D. It can be hard to determine if red cars or black cars are more visible on modern highways.
Answer: C. It is not possible to separate the effect of car color from the type of people who choose
to drive red cars.
, Q3: the following best describes what this means?
A. There are too many variables involved in traffic accidents to isolate the effect of car color.
B. The accidents used in the study might not be a random sample of all accidents.
C. It is not possible to separate the effect of car color from the type of people who choose to
drive red cars.
D. It can be hard to determine if red cars or black cars are more visible on modern highways.
Answer: C. It is not possible to separate the effect of car color from the type of people who choose
to drive red cars.
Q4: A new headache remedy was given to a group of 25 subjects who had headaches. Four hours
after taking the new remedy, 20 of the subjects reported that their headaches had
disappeared. From this information, you conclude
A. that the remedy is effective for the treatment of headaches.
B. nothing because the sample size is too small
C. nothing because there is no control group for comparison.
D. that the new treatment is better than aspirin.
Answer: C. nothing because there is no control group for comparison.
Q5: A gardener wants to try different combinations of fertilizer (none, 1 cup, 2 cups) and mulch
(none, wood chips, pine needles, plastic) to determine which combination produces the
highest yield for a variety of green beans. He has 60 green-bean plants to use in the
experiment. If he wants an equal number of plants to be assigned to each treatment, how
many plants will be assigned to each treatment?
A. 1
B. 3
C. 4
D. 5
Answer: D. 5
Q6: plants to be assigned to each treatment, how many plants will be assigned to each
treatment?
A. 1
B. 3
C. 4
D. 5
Answer: D. 5
