Question 1

Answer the question.
-Which of the following describes the bias that occurs when researchers select their sample in such a way that it is unlikely to be representative of the population?

Accepted Answer

A) Double-blind bias 
B) Selection bias 
C) Availability bias 
D) Participation bias

Question 2

Determine whether the study involves selection bias, participation bias, both selection bias and participation bias, orneither.
-A researcher published this survey result: "74% of people would be willing to spend 10 percent more for energy from a non-polluting source". The survey question was announced on a national
Radio show and 1200 listeners responded by calling in.

Accepted Answer

A) No bias 
B) Selection bias only 
C) Participation bias and selection bias 
D) Participation bias only

Question 3

Provide an appropriate response.
-Suppose that you want to construct a pie chart to represent the following data. $$\begin{array} { l | c } 
\text { Blood Type } & \text { Frequency } \
\hline \text { O } & 90 \
\text { A } & 84 \
\text { B } & 18 \
\text { AB } & 8
\end{array}$$ Explain how you would calculate the angle for the pie-shaped piece corresponding to the
blood type O.

Accepted Answer

The answer of Provide an appropriate response.
-Suppose that you want...

Question 4

Choose the best wording for the question in the study.
-A researcher wants to determine the level of support for the war. Which of the following questions would produce the most accurate results?

Accepted Answer

A) Do you agree that the troops should be brought home to safety now? 
B) How do you feel about the war? 
C) Do you support the troops? 
D) Do you agree that it is important to defend our country against terrorism?

Question 5

State whether you think that the variables have strong positive correlation, weak positive correlation, strong negativecorrelation, weak negative correlation, or no correlation.
-Number of appliances sold and revenue of appliance store

Accepted Answer

A) No correlation 
B) Weak positive correlation 
C) Weak negative correlation 
D) Strong positive correlation 
E) Strong negative correlation

Question 6

Create a graphical display for the data given. You may choose any graphic type that you feel is appropriate. Write a fewsentences explaining why you chose this type of display and a few sentences describing any interesting patterns in thedata.
-The table below shows the number of AIDS diagnoses for the United Kingdom by year. $$\begin{array} { c | c | l } 
\text { Year of diagnosis } & \text { Male } & \text { Female } \
\hline 1993 & 1549 & 237 \
1994 & 1628 & 225 \
1995 & 1487 & 282 \
1996 & 1164 & 270 \
1997 & 857 & 216 \
1998 & 592 & 192 \
1999 & 556 & 189 \
2000 & 572 & 236
\end{array}$$

Accepted Answer

The answer of Create a graphical display for the data...

Question 7

Construct a pie chart representing the given data set.
-$\begin{array} { c c } 
\hline \text { Favorite Beverage } & \text { Number of responses } \
\hline \text { Cola } & 170 \
\text { Juice } & 105 \
\text { Milk } & 115 \
\text { Tea } & 155 \
\text { Water } & 75 \
\hline
\end{array}$

Accepted Answer

A) 
 
B) 
 
C) 
 
D)

Question 8

The stack plot below shows the value of each of Danny's investments. The stack plot contains three regions. Theuppermost unshaded region represents the value of Danny's investment in individual stocks. The center shaded regionrepresents the value of Danny's investment in mutual funds and the bottom region in black represents the value ofDanny's investment in a CD. The thickness of a region at a particular time tells you its value at that time.  Use the graph to answer the question.
-In which year was the value of Danny's investment in individual stocks the least?

Accepted Answer

A) year 1 
B) year 8 
C) year 7 
D) year 0

Question 9

A sample statistic and margin of error are given. Find the confidence interval likely to contain the population parameterof interest and answer the question.
-A poll conducted the day before the student-body presidential election at a midwestern university showed that 53.0 percent favored Mario, the rest favoring Yin Ling. The margin of error was 5.0
Percentage points. Should Yin Ling have conceded the election?

Accepted Answer

A) 48% to 53.0%; no 
B) 53.0% to 58%; yes 
C) 48% to 58%; no 
D) 50.5% to 55.5%; yes

Question 10

A statement is made about correlation. State whether the correlation is positive or negative and whether the correlation ismost likely due to coincidence, a common underlying cause, or a direct cause.
-Towns with a lot of churches had a lot of homicides last year. Towns with fewer churches had fewer homicides.

Accepted Answer

A) Positive correlation; direct cause 
B) Negative correlation; common underlying cause 
C) Positive correlation; common underlying cause 
D) Positive correlation; coincidence

Question 11

Answer the question.
-The strengths of the last 5 major earthquakes to hit California have differed by factors of 10. If you were to display data describing the strengths of these earthquakes what could you use to make the
Graph more readable?

Accepted Answer

A) A stack plot 
B) An exponential scale 
C) A color coded map 
D) A three dimensional graph

Question 12

A sample statistic and margin of error are given. Find the confidence interval likely to contain the population parameterof interest and answer the question.
-Following the Republican National Convention, a poll of voters in a Central Illinois community showed that 58.1% would choose the Republican ticket to win over the Democrat ticket no matter
Whom the Democrats chose for vice-president. The margin of error was 4.2 percentage points.
Should the Democrats expect to lose Central Illinois?

Accepted Answer

A) 53.9% to 62.3%; yes 
B) 49.7% to 58.1%; no 
C) 58.1% to 62.3%; yes 
D) 56% to 60.2%; yes

Question 13

Solve the problem.
-A researcher suspects that pesticides in foods cause cancer. Suggest some ways that she
could go about establishing causality. Refer to the six guidelines for establishing causality.
For each guideline suggest some research that should be pursued. Discuss any challenges
that the researcher would face in establishing causality.

Accepted Answer

The answer of Solve the problem.
-A researcher suspects that pesticides...

Question 14

Answer the question.
-Which of the following quantities of interest would be the most difficult to define?

Accepted Answer

A) The paint with the best looking finish 
B) The least expensive brand of paint 
C) How water resistant a brand of paint is 
D) The levels of lead in various brands of paint

Question 15

Choose the best wording for the question in the study.
-If you wanted to determine if your customers are satisfied with the selection in your store, which of the following survey questions would give you the most accurate results?

Accepted Answer

A) Is our selection as good as the selection of our competitor? 
B) Is there anything you would have purchased if our stock was not without it? 
C) Do you agree that our selection is better than our competitor? 
D) Are you satisfied with the selection at this store?

Question 16

Answer the question.
-Which of the following describes the process by which scientists examine each others' research?

Accepted Answer

A) Peer review 
B) Considering the conclusion 
C) Interpretation 
D) Participation review

Question 17

In order to answer the given question, which of the following types of study would be the most appropriate: anexperiment without blinding, an experiment with single blinding, an experiment with double blinding, an observationalstudy, or a case-control study?
-Does the new medication relieve depression?

Accepted Answer

A) Experiment with double blinding 
B) Experiment without blinding 
C) Case-control study 
D) Observational study 
E) Experiment with single blinding

Question 18

Answer as requested.
-Which of the following best describes our level of confidence in causality when we have discovered a correlation but cannot yet determine whether the correlation implies causality?

Accepted Answer

A) Cause beyond reasonable doubt 
B) Possible cause 
C) Probable cause 
D) Absolute certainty

Question 19

Answer the question.
-Double blinding is used in an experiment to avoid which of the following problems?

Accepted Answer

A) If improvement is observed in a patient, it is difficult to know whether this is due to the treatment or the placebo effect 
B) If the researcher knows that the patient received the treatment, the researcher may also experience health changes 
C) If the patient knows that he received the placebo and not the treatment he may be angry and fail to tell the truth 
D) If an experimenter knows whether the patient has received the treatment or the placebo, this may influence how he or she questions the patient

Question 20

Use the graph to answer the question.
- Identify the utility that accounts for over half the total bill in two months.

Accepted Answer

A) Gas 
B) Water 
C) Electric 
D) No single utility accounts for more than half the total bill in two months.

Exam 5: Statistical Reasoning

Answer the question. -Which of the following describes the bias that occurs when researchers select their sample in such a way that it is unlikely to be representative of the population?

Choose the best wording for the question in the study. -A researcher wants to determine the level of support for the war. Which of the following questions would produce the most accurate results?

State whether you think that the variables have strong positive correlation, weak positive correlation, strong negativecorrelation, weak negative correlation, or no correlation. -Number of appliances sold and revenue of appliance store

Answer the question. -The strengths of the last 5 major earthquakes to hit California have differed by factors of 10. If you were to display data describing the strengths of these earthquakes what could you use to make the Graph more readable?

Answer the question. -Which of the following quantities of interest would be the most difficult to define?

Choose the best wording for the question in the study. -If you wanted to determine if your customers are satisfied with the selection in your store, which of the following survey questions would give you the most accurate results?

Answer the question. -Which of the following describes the process by which scientists examine each others' research?

Answer as requested. -Which of the following best describes our level of confidence in causality when we have discovered a correlation but cannot yet determine whether the correlation implies causality?

Answer the question. -Double blinding is used in an experiment to avoid which of the following problems?

Use the graph to answer the question. - Identify the utility that accounts for over half the total bill in two months.