STA1510 EXAM PACK 2024
On June 2, 2007, a nurse in Wales accidentally injected an 85-year-old patient with a
lethal amount of insulin during a home visit. The syringes used to inject insulin are
typically marked with insulin units instead of the usual milliliters. Finding herself
without an insulin syringe on hand, the nurse retrieved a new syringe from her car.
She did not notice, however, that the syringe she grabbed was marked in milliliters
instead of insulin units. If 1 milliliter equals 100 insulin units, how many milliliters
should the patient have been given if she had been prescribed 36 units? - ANSWER
1 milliliter = 100 units so 0.01 milliliter = 1 unit. It follows that 0.36 milliliters = 36
units. So she should have injected the patient with 0.36 milliliters.
Which of the following statements is true? - ANSWER The mean and standard
deviation are sensitive to outliers
A researcher did experiments with six sets of animals with each set having five
animals each. In a paper accepted into the Journal of Experimental Medicine the
researcher reported the percentage of each set of five that had successful outcomes.
Here are the numbers this guy reported: 53, 58, 63, 46, 48, and 57. What is wrong
with these numbers? - ANSWER they can't be results on sets of five animals unless
they are multiples of 20 percent
Which of the following statements do you think could possibly be true? - ANSWER
The number of students enrolled at Midville University decreased by 10.4% last year.
The well-respected journal Science, in an article on insects and plants, mentioned a
California field that produced 750,000 melons per acre. How do you react to that? It
may help you know that an acre is 43,560 square feet. - ANSWER This is
unreasonable, suggesting about 17 melons per square foot
The claim has been made that over 4 million women in the U.S. are battered to
death each year by a spouse or boyfriend. What is wrong with this claim? -
ANSWER Only about 2.4 million people die in the U.S. each year from all causes.
The following graph is from the Florida Department of Law Enforcement. It has been
used to argue that murder decreased in Florida once a 2005 "Stand Your Ground"
law was enacted. Does the graph actually support that statement? - ANSWER No.
The y-axis is inverted so the dip after 2005 is actually a spike.
What do we mean by "human inference?" - ANSWER Off-hand phrase taken to
mean inference we make from statistical constructs
If the standard deviation of a set of data is computed to be 4, then the variance is: -
ANSWER 2
In a study reported in the Chicago tribune, in 2012, twenty-four students were fatally
shot during the school year that ended June 15, four fewer than in the 2010-11 year.
,But the overall shooting toll —319—was the highest in four years and a nearly 22
percent increase from 2011. What was the total number of shootings in 2011? -
ANSWER 261
What can one say about the sampling distribution of a sample statistic based on a
simple random sample? - ANSWER it is about bell-shaped and peaks above the
parameter
You ask a question to a random sample of 1000 adults in California (population 38.3
million people) and to a separate random sample of 1000 adults in Indiana
(population 6.6 million people). You make separate 95% confidence statements
about the percent of all adults in each state who agree. Your margin of error for
Indiana is:
(you may find the following generic confidence interval information useful) -
ANSWER the same as in California, because the two samples are the same size.
The distribution shown here represents the sampling distribution that resulted from
44 simple random samples, each of size 50, taken from a manufactured population
of 250 people. In each case the proportion of sampled individuals who agreed that
Facebook was doing an adequate job protecting users' data was recorded. About
what percentage of the time did a sample percentage between 21% and 36% occur?
- ANSWER 80%
Which of the following is a strategy for reducing non-sampling errors? - ANSWER
Use of incentives for non-responders
In September of 2016, an article in The Denver Post declared "Colorado in Dead
Heat Between Hillary Clinton and Donald Trump." The article went on to say: "The
survey by CNN and ORC International found 42 percent of likely Colorado voters
backed Trump compared to the 41 percent who supported Clinton; a statistical tie
given the margin of error of 3.5 percentage points." The article did not report the
sample size. However, if this margin of error is a 95% margin of error, what would
the sample size have to be, more or less?
(You might find the following generic confidence interval information useful:) -
ANSWER About 816
A survey was conducted by Playboy, asking questions about the sex lives of 5,000
U.S. University and College students. One question asked: "Are you in a nude
picture on someone's camera phone?" 34 percent said "yes". Other samples of size
5,000, if asked the same question, would likely not produce a sample percentage of
34%. What is this variability called? - ANSWER Sampling variability
A survey was conducted by Playboy, asking questions about the sex lives of 5,000
U.S. University and College students. One question asked: "Are you in a nude
picture on someone's camera phone?" 34 percent said "yes". Name at least one
error you'd expect this survey to suffer from even if all 15.9 million College and
University students in the U.S. had answered, and not just 5,000. - ANSWER Error
caused by fabricated responses
, Recall the article about the Harris Poll that was discussed in one of our BN
assignments. Harris is a major polling organization that refuses to accompany their
poll reports with a margin of error. What is one reason that was given for such a bold
omission? - ANSWER Harris recognizes that there are many sources of error that
are not addressed by the MOE, so reporting it might be misleading.
A Dean of Admissions at U.K. once tallied up the ACT scores for ALL entering
freshman for that year and reported that the average was 25. He then attached a
margin of error at the urging of a faculty member in the audience. That faculty
member was: - ANSWER confused, because the Dean's figure was not subject to
any sampling variability
A Ph.D. candidate in the College of Education once defended her misleading and
confusing questionnaire by arguing that her margin of error was low, only about 3%.
This argument is: - ANSWER confused, because the margin of error has nothing to
do with poor questionnaire designs
Please read the following article from CBS News. What is the sample for the CBS
News Poll?
Title: Poll: Majority of Americans Back Stricter Gun Laws
Authors: Sarah Dutton, Jennifer De Pinto, Anthony Salvanto, Fred Backus and Leigh
Ann Caldwell
Source: CBS News January 17, 2013
As the president outlined sweeping new proposals aimed to reduce gun violence, a
new CBS News/ New York Times poll found that Americans back the central
components of the president's proposals, including background checks, a national
gun sale database, limits on high capacity magazines and a ban on semi-automatic
weapons. Asked if they generally back stricter gun laws, more than half of
respondents—54%—support stricter gun laws ... That is a jump from April—before
the Newtown and Aurora shootings—when only 39% backed stricter gun laws but
about the same as ten years ago.
...
This poll was conducted by telephone from January 11-15, 2 - ANSWER 1,110
adults contacted by phone
Please read the following article from CBS News. What is the population for the CBS
News Poll?
Title: Poll: Majority of Americans Back Stricter Gun Laws
On June 2, 2007, a nurse in Wales accidentally injected an 85-year-old patient with a
lethal amount of insulin during a home visit. The syringes used to inject insulin are
typically marked with insulin units instead of the usual milliliters. Finding herself
without an insulin syringe on hand, the nurse retrieved a new syringe from her car.
She did not notice, however, that the syringe she grabbed was marked in milliliters
instead of insulin units. If 1 milliliter equals 100 insulin units, how many milliliters
should the patient have been given if she had been prescribed 36 units? - ANSWER
1 milliliter = 100 units so 0.01 milliliter = 1 unit. It follows that 0.36 milliliters = 36
units. So she should have injected the patient with 0.36 milliliters.
Which of the following statements is true? - ANSWER The mean and standard
deviation are sensitive to outliers
A researcher did experiments with six sets of animals with each set having five
animals each. In a paper accepted into the Journal of Experimental Medicine the
researcher reported the percentage of each set of five that had successful outcomes.
Here are the numbers this guy reported: 53, 58, 63, 46, 48, and 57. What is wrong
with these numbers? - ANSWER they can't be results on sets of five animals unless
they are multiples of 20 percent
Which of the following statements do you think could possibly be true? - ANSWER
The number of students enrolled at Midville University decreased by 10.4% last year.
The well-respected journal Science, in an article on insects and plants, mentioned a
California field that produced 750,000 melons per acre. How do you react to that? It
may help you know that an acre is 43,560 square feet. - ANSWER This is
unreasonable, suggesting about 17 melons per square foot
The claim has been made that over 4 million women in the U.S. are battered to
death each year by a spouse or boyfriend. What is wrong with this claim? -
ANSWER Only about 2.4 million people die in the U.S. each year from all causes.
The following graph is from the Florida Department of Law Enforcement. It has been
used to argue that murder decreased in Florida once a 2005 "Stand Your Ground"
law was enacted. Does the graph actually support that statement? - ANSWER No.
The y-axis is inverted so the dip after 2005 is actually a spike.
What do we mean by "human inference?" - ANSWER Off-hand phrase taken to
mean inference we make from statistical constructs
If the standard deviation of a set of data is computed to be 4, then the variance is: -
ANSWER 2
In a study reported in the Chicago tribune, in 2012, twenty-four students were fatally
shot during the school year that ended June 15, four fewer than in the 2010-11 year.
,But the overall shooting toll —319—was the highest in four years and a nearly 22
percent increase from 2011. What was the total number of shootings in 2011? -
ANSWER 261
What can one say about the sampling distribution of a sample statistic based on a
simple random sample? - ANSWER it is about bell-shaped and peaks above the
parameter
You ask a question to a random sample of 1000 adults in California (population 38.3
million people) and to a separate random sample of 1000 adults in Indiana
(population 6.6 million people). You make separate 95% confidence statements
about the percent of all adults in each state who agree. Your margin of error for
Indiana is:
(you may find the following generic confidence interval information useful) -
ANSWER the same as in California, because the two samples are the same size.
The distribution shown here represents the sampling distribution that resulted from
44 simple random samples, each of size 50, taken from a manufactured population
of 250 people. In each case the proportion of sampled individuals who agreed that
Facebook was doing an adequate job protecting users' data was recorded. About
what percentage of the time did a sample percentage between 21% and 36% occur?
- ANSWER 80%
Which of the following is a strategy for reducing non-sampling errors? - ANSWER
Use of incentives for non-responders
In September of 2016, an article in The Denver Post declared "Colorado in Dead
Heat Between Hillary Clinton and Donald Trump." The article went on to say: "The
survey by CNN and ORC International found 42 percent of likely Colorado voters
backed Trump compared to the 41 percent who supported Clinton; a statistical tie
given the margin of error of 3.5 percentage points." The article did not report the
sample size. However, if this margin of error is a 95% margin of error, what would
the sample size have to be, more or less?
(You might find the following generic confidence interval information useful:) -
ANSWER About 816
A survey was conducted by Playboy, asking questions about the sex lives of 5,000
U.S. University and College students. One question asked: "Are you in a nude
picture on someone's camera phone?" 34 percent said "yes". Other samples of size
5,000, if asked the same question, would likely not produce a sample percentage of
34%. What is this variability called? - ANSWER Sampling variability
A survey was conducted by Playboy, asking questions about the sex lives of 5,000
U.S. University and College students. One question asked: "Are you in a nude
picture on someone's camera phone?" 34 percent said "yes". Name at least one
error you'd expect this survey to suffer from even if all 15.9 million College and
University students in the U.S. had answered, and not just 5,000. - ANSWER Error
caused by fabricated responses
, Recall the article about the Harris Poll that was discussed in one of our BN
assignments. Harris is a major polling organization that refuses to accompany their
poll reports with a margin of error. What is one reason that was given for such a bold
omission? - ANSWER Harris recognizes that there are many sources of error that
are not addressed by the MOE, so reporting it might be misleading.
A Dean of Admissions at U.K. once tallied up the ACT scores for ALL entering
freshman for that year and reported that the average was 25. He then attached a
margin of error at the urging of a faculty member in the audience. That faculty
member was: - ANSWER confused, because the Dean's figure was not subject to
any sampling variability
A Ph.D. candidate in the College of Education once defended her misleading and
confusing questionnaire by arguing that her margin of error was low, only about 3%.
This argument is: - ANSWER confused, because the margin of error has nothing to
do with poor questionnaire designs
Please read the following article from CBS News. What is the sample for the CBS
News Poll?
Title: Poll: Majority of Americans Back Stricter Gun Laws
Authors: Sarah Dutton, Jennifer De Pinto, Anthony Salvanto, Fred Backus and Leigh
Ann Caldwell
Source: CBS News January 17, 2013
As the president outlined sweeping new proposals aimed to reduce gun violence, a
new CBS News/ New York Times poll found that Americans back the central
components of the president's proposals, including background checks, a national
gun sale database, limits on high capacity magazines and a ban on semi-automatic
weapons. Asked if they generally back stricter gun laws, more than half of
respondents—54%—support stricter gun laws ... That is a jump from April—before
the Newtown and Aurora shootings—when only 39% backed stricter gun laws but
about the same as ten years ago.
...
This poll was conducted by telephone from January 11-15, 2 - ANSWER 1,110
adults contacted by phone
Please read the following article from CBS News. What is the population for the CBS
News Poll?
Title: Poll: Majority of Americans Back Stricter Gun Laws
