Question 1

Solve the problem.
-For the study described below, identify the sample statistic. A manufacturer of light bulbs wants to determine the average lifetime of its 75 -watt light bulbs. Among 120 randomly selected 75 -watt light bulbs, the average lifetime was 1007 hours.

Accepted Answer

A)  120 , the number of light bulbs in the sample 
B)  The average lifetime of all 75-watt light bulbs manufactured by the company 
C)  The average lifetime of the 120 randomly selected 75-watt light bulbs 
D)  The 120 randomly selected 75 -watt light bulbs

Question 2

State whether you think that the variables have strong positive correlation, weak positive correlation, strong negativecorrelation, weak negative correlation, or no correlation.
-Hours of exercise per week and blood pressure.

Accepted Answer

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

Question 3

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?
-Are short women more likely to develop breast cancer than tall women?

Accepted Answer

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

Question 4

Make a bar graph to represent the data.
-The following table shows the number of female infants born at Hospital X on New Year's
Day (Jan. 1). Create a vertical bar graph. $$\begin{array} { c | c } 
& \begin{array} { c } 
\text { No. of Female } \
\text { Year }
\end{array} \
\hline \text { Infants Born Jan } 1 \
\hline 1970 & 21 \
1971 & 12 \
1972 & 18 \
1973 & 30 \
1974 & 27 \
1975 & 24
\end{array}$$

Accepted Answer

The answer of Make a bar graph to represent the...

Question 5

Describe how you would apply the five basic steps of a statistical study to the given issue.
-You want to know the percentage of college seniors who regret their choice of major.

Accepted Answer

The answer of Describe how you would apply the five...

Question 6

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.
-People who eat a lot of junk food are heavier, on the whole, than those who do not.

Accepted Answer

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

Question 7

Identify which of these types of sampling is used: simple random, stratified, systematic, or convenience.
-The name of each contestant is written on a separate card, the cards are placed in a bag, and three names are picked from the bag.

Accepted Answer

A) Stratified 
B) Systematic 
C) Simple random 
D) Convenience

Question 8

Answer as requested.
-Suppose that there is perfect positive correlation between the number of hours studied for a test and score on the test. Which of the following statements must be true? More than one statement
May be true.
A: If we know the number of hours a given student studied, we will be able to perfectly predict
Their test score.
B: If Anne studied twice as long as Manuel, she will score twice as much.
C: If Lu Yi studied ten hours more than Andrea, Lu Yi will score ten points more than Andrea.
D: All data points lie perfectly on a horizontal line.

Accepted Answer

A) B and C 
B) All statements are true 
C) A 
D) A and D

Question 9

State whether the scatter diagram shows strong positive correlation, weak positive correlation, strong negativecorrelation, weak negative correlation, or no correlation.
-

Accepted Answer

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

Question 10

Identify the variable as either qualitative or quantitative.
-The movie critics' ratings of the new movie on a scale of $0 - 10$ where $10 =$ the best movie ever seen and $0 =$ the worst movie ever seen

Accepted Answer

A)  Qualitative 
B)  Quantitative

Question 11

Solve the problem.
-For the study described below, identify the sample statistic. 1500 American women working for large companies were polled to determine the percentage that
Felt that women were under represented in management positions in their company.

Accepted Answer

A) The number of women polled. 
B) The 1500 women polled 
C) The percentage of women in the sample who feel that women are under represented in management positions in their company. 
D) The percentage of American women working for large companies who feel that women are under represented in management positions in their company.

Question 12

Choose the best wording for the question in the study.
-Proposition EZ proposes to raise the state sales tax by one quarter of a percent. The proceeds will be earmarked for music education in the public schools. If you want to determine whether or not it
Will pass, which of the following survey questions will give you the most accurate results?

Accepted Answer

A) Do you know which proposition will raise state sales tax and fund music education? 
B) Are you planning to vote for Proposition EZ which will raise state sales taxes and support music education? 
C) Will you vote for proposition EZ which will raise the amount of state sales tax that you pay every year? 
D) Do you believe that music education is important?

Question 13

Use the guidelines to evaluate the study. From the information given, what is the biggest flaw in the study?
-A medical researcher randomly selects 500 Japanese people and 500 Americans. She questions the 1000 people. She finds that the Americans work longer hours on average and also that the
Americans have a higher rate of heart disease. She concludes that working longer hours is
Associated with a higher incidence of heart disease.

Accepted Answer

A) Variables are hard to define/measure 
B) Selection bias 
C) The source 
D) Participation bias 
E) Confounding variables

Question 14

Construct a line chart for the data.
-The table shows the price of a volatile stock from the months January through December of the same year as determined by the closing price on the last trading day of the month. The price is
Rounded to the nearest dollar. $\begin{array}{l}
\begin{array} { c c c c c c c c c c c c } 
\text { Jan } & \text { Feb } & \text { Mar } & \text { Apr } & \text { May } & \text { Jun } & \text { Jul } & \text { Aug } & \text { Sep } & \text { Oct } & \text { Nov } & \text { Dec } \
\hline 32 & 70 & 73 & 111 & 184 & 87 & 45 & 42 & 67 & 87 & 94 & 111
\end{array}\
\text { Construct a time series line chart for the data. }
\end{array}$

Accepted Answer

A) 
 
B) 
 
C) 
 
D)  None of the above

Question 15

Use the guidelines to evaluate the study. From the information given, what is the biggest flaw in the study?
-A pharmaceutical company conducted a study to test the effectiveness of its new anti-depression medication. 500 adults suffering from depression were selected at random and were randomly
Assigned to either a treatment group or a placebo group. The experiment was double blind. The
Results were analyzed by the company.

Accepted Answer

A) Selection bias 
B) The setting may not encourage honest responses 
C) The source of the study 
D) Confounding variables 
E) Variables are difficult to define/measure

Question 16

Answer the question.
-The bar graph below shows the average cost of renting a studio in a certain city in each of
the years 1994 through 1998.  By what percentage does the average rental price increase from 1994 to 1995? Obtain a
truncated version of the graph by sliding a piece of paper over the bottom portion of the
graph so that the scale on the vertical axis starts at 300. In the truncated graph, by what
percentage does the price appear to increase from 1994 to 1995? Why is the truncated
graph misleading?

Accepted Answer

The answer of Answer the question.
-The bar graph below shows...

Question 17

The graph below shows estimated world population for the period  $4000 \mathrm { BC } - 2000 \mathrm { AD }$. Note that the logarithm of the world population and not actual population is plotted on the vertical axis. This means, for example, that when the graph reaches 7 on the vertical scale, world population is $10 ^ { 7 }$ and when the graph reaches 9 on the vertical scale, world population is $10 ^ { 9 }$.  Use the graph to answer the question.
-How does world population in the year 1000 AD compare with world population in the year 2000 BC?

Accepted Answer

A) The 1000 AD population is roughly one million larger than the 2000 BC population. 
B) The 1000 AD population is roughly 14% larger than the 2000 BC population. 
C) The 1000 AD population is roughly ten million larger than the 2000 BC population. 
D) The 1000 AD population is roughly ten times as large as the 2000 BC population.

Question 18

Use the graph to answer the question.
-The following chart shows the percentage of cigarette smokers in Gotham City.  In which year does the percentage of men who smoke exceed the percentage of women who smoke by roughly 9 percentage points.

Accepted Answer

A) None of the above 
B) 1975 
C) 1995 
D) 1985

Question 19

Make a scatter diagram for the data.
-The table shows the life expectancy at birth for females and per capita GDP for nine countries. (Data for 1995) $$\begin{array} { l | c | c } 
\text { Country } & \begin{array} { l } 
\text { Life Expectancy } \
\text { at birth (female) }
\end{array} & \text { Per Capita GDP (dollars) } \
\hline \text { Afghanistan } & 45 & 200 \
\text { Chile } & 78 & 7000 \
\text { Ghana } & 58 & 1500 \
\text { Guatemala } & 68 & 3000 \
\text { Kenya } & 54 & 1200 \
\text { Spain } & 81 & 12,700 \
\text { Thailand } & 72 & 5500 \
\text { New Zealand } & 80 & 15,700 \
\text { United States } & 80 & 24,700
\end{array}$$ Plot per capita GDP on the horizontal axis and life expectancy on the vertical axis.

Accepted Answer

A) 
 
B) 
 
C) 
 
D)

Question 20

Describe how you would apply the five basic steps of a statistical study to the given issue.
-As a marketing executive for a computer company you wish to determine the average
length of time that owners of personal computers in the U.S. keep a computer before
buying a newer model.

Accepted Answer

The answer of Describe how you would apply the five...

Exam 5: Statistical Reasoning

Solve the problem. -For the study described below, identify the sample statistic. A manufacturer of light bulbs wants to determine the average lifetime of its 75 -watt light bulbs. Among 120 randomly selected 75 -watt light bulbs, the average lifetime was 1007 hours.

State whether you think that the variables have strong positive correlation, weak positive correlation, strong negativecorrelation, weak negative correlation, or no correlation. -Hours of exercise per week and blood pressure.

Describe how you would apply the five basic steps of a statistical study to the given issue. -You want to know the percentage of college seniors who regret their choice of major.

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. -People who eat a lot of junk food are heavier, on the whole, than those who do not.

Identify which of these types of sampling is used: simple random, stratified, systematic, or convenience. -The name of each contestant is written on a separate card, the cards are placed in a bag, and three names are picked from the bag.

State whether the scatter diagram shows strong positive correlation, weak positive correlation, strong negativecorrelation, weak negative correlation, or no correlation. -

Identify the variable as either qualitative or quantitative. -The movie critics' ratings of the new movie on a scale of 0−100 - 100−10 where 10=10 =10= the best movie ever seen and 0=0 =0= the worst movie ever seen

Solve the problem. -For the study described below, identify the sample statistic. 1500 American women working for large companies were polled to determine the percentage that Felt that women were under represented in management positions in their company.

Use the graph to answer the question. -The following chart shows the percentage of cigarette smokers in Gotham City. In which year does the percentage of men who smoke exceed the percentage of women who smoke by roughly 9 percentage points.

Describe how you would apply the five basic steps of a statistical study to the given issue. -As a marketing executive for a computer company you wish to determine the average length of time that owners of personal computers in the U.S. keep a computer before buying a newer model.

Identify the variable as either qualitative or quantitative. -The movie critics' ratings of the new movie on a scale of $0 - 10$ where $10 =$ the best movie ever seen and $0 =$ the worst movie ever seen