Midterm/ 115 Qs with Certified Solutions.
Determine whether the sampling method described below appears to be sound or is flawed.
In a survey of 538 subjects, the following question was posted on a newspaper's website: "In
your view, are nuclear plants safe?" The survey subjects were Internet users who chose to
respond to the question posted on the electronic edition of the newspaper. - Answer: - It is
flawed because it is a voluntary response sample.
Which of the following is NOT a voluntary response sample? - Answer: - Quiz scores from a
college level statistics course are analyzed to determine student progress.
Determine whether the underlined number is a statistic or a parameter.
,In a study of all 2669 students at a college, it is found that 25% own a computer - Answer: -
Parameter because the value is a numerical measurement describing a characteristic of a
population
State whether the data described below are discrete or continuous, and explain why.
The heights of trees in a forest - Answer: - The data are continuous because the data can take
on any value in an interval
Which sampling method divides the population up into sections, randomly selects some of
those sections, then chooses all the members from the selected sections to study? - Answer: -
Cluster
What is a scatterplot and how does it help us? - Answer: - A scatterplot is a graph of paired (x, y)
quantitative data. It provides a visual image of the data plotted as points, which helps show any
patterns in the data.
Determine whether the given source has the potential to create a bias in a statistical study.
An article in Journal of Nutrition (Vol. 130, No. 8) noted that chocolate is rich in flavonoids. The
article notes "regular consumption of foods rich in flavonoids may reduce the risk of coronary
heart disease." The study received funding from Mars, Inc., the candy company, and the
Chocolate Manufacturers Association. - Answer: - The researchers may have been more inclined
to provide favorable results because funding was provided by a party with a definite interest.
The bias could have been avoided if the researchers were not paid by the candy company and
the chocolate manufacturers.
Determine whether the sampling method described below appears to be sound or is flawed.
, In a survey of 688 subjects, the following question was posted on a newspaper's website: "In
your view, are nuclear plants safe?" The survey subjects were Internet users who chose to
respond to the question posted on the electronic edition of the newspaper. - Answer: - It is
flawed because it is a voluntary response sample.
Determine whether the underlined number is a statistic or a parameter.
In a study of all 1184 seniors at a college, it is found that 25% own a vehicle - Answer: -
Parameter because the value is a numerical measurement describing a characteristic of a
population.
Determine whether the data described below are qualitative or quantitative and explain why.
The times of birth of babies born at a certain hospital - Answer: - The data are quantitative
because they consist of counts or measurements
State whether the data described below are discrete or continuous, and explain why.
The volumes of different rooms - Answer: - The data are continuous because the data can take
on any value in an interval
Determine whether the given value is a statistic or a parameter.
A homeowner measured the voltage supplied to his home on a random sample of 48 days, and
the average mean is 102.9 volts - Answer: - The given value is a statistic for the year because the
data collected represent a sample.
The sinking of the Titanic on April 15, 1912, is one of the most infamous disasters in history. A
population of 1503 passengers and crew died when the Titanic sank approximately 400 miles