Question 1

Solve the problem.
-A researcher finds a positive correlation between the amount of coffee people drink and
anxiety level. Can you conclude that drinking coffee causes anxiety? Propose other
explanations for the correlation. Suggest some ways that the researcher could go about
establishing causality. Refer to the six guidelines for establishing causality.

Accepted Answer

The answer of Solve the problem.
-A researcher finds a positive...

Question 2

Answer the question.
-The graph below shows the approximate annual percentage growth rate in world
population for the years 1960 through 2010. Data is estimated by the UN Census Bureau.  Why must the graph be interpreted with care? If the graph is not interpreted with care
what misleading impression might one have of world population during the period
1960-2010? In which year during the period 1960-2010 is estimated world population the
greatest? During which years did world population increase at the fastest rate?
Summarize the overall trends in world population during the period 1960-2010.

Accepted Answer

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

Question 3

Answer the question.
-The graph below shows estimated world population for the period 4000 BC $4000 \mathrm { BC } - 2000 \mathrm { AD }$ 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 $10 ^ { 9 }$ .  Why must the graph be interpreted with care? If the graph is not interpreted with care
what misleading impression might one have of world population during the period 4000
BC - 2000 AD? Why do you think that the graph was presented in this form?

Accepted Answer

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

Question 4

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 5

Make a bar graph to represent the data.
-Construct a vertical bar graph for the relative frequencies given. $$\begin{array} { l c c } 
\begin{array} { c } 
\text { Blood } \
\text { type }
\end{array} & \text { Frequency } & \begin{array} { c } 
\text { Relative } \
\text { frequency }
\end{array} \
\hline \mathrm { O } & 22 & 0.44 \
\mathrm {~A} & 19 & 0.38 \
\mathrm {~B} & 6 & 0.12 \
\mathrm { AB } & 3 & 0.06
\end{array}$$

Accepted Answer

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

Question 6

Use the guidelines to evaluate the study. Discuss flaws that you see in the study.
-A TV show announced that their survey had revealed that 87% of Americans would rather
be free than rich.

Accepted Answer

The answer of Use the guidelines to evaluate the study....

Question 7

Make a bar graph to represent the data.
-The following table shows the number of inches of rainfall measured at City X during the
following days. Create a horizontal bar graph. $$\begin{array} { r | r } 
\text { Day } & \begin{array} { r } 
\text { No. of Inches } \
\text { of Rainfall }
\end{array} \
\hline \text { April 9 } & 1.26 \
\text { April 24 } & 1.94 \
\text { May 9 } & 3.26 \
\text { May 24 } & 2.54 \
\text { June 9 } & 2.02 \
\text { June 24 } & 1.86
\end{array}$$

Accepted Answer

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

Question 8

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

Accepted Answer

The answer of Use the graph to answer the question.
-The...

Question 9

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 gives information about U.S. families with children under the age of 18.
The table shows the percentage of these families that are two-parent families, the
percentage that are maintained by a single mother, and the percentage that are maintained
by a single father. $$\begin{array}{l}
\text { U.S. Families with Children Under } 18\
\begin{array} { c | c | c | c } 
\text { Year } & \text { Two-parent } & \text { Single mother } & \text { Single father } \
\hline 1981 & 77.6 \% & 20.0 \% & 2.4 \% \
1984 & 74.2 \% & 22.9 \% & 2.8 \% \
1987 & 73.0 \% & 23.7 \% & 3.2 \% \
1990 & 71.9 \% & 24.2 \% & 3.9 \% \
1993 & 69.8 \% & 25.9 \% & 4.3 \% \
1996 & 68.4 \% & 26.6 \% & 5.0 \% \
1999 & 68.2 \% & 26.3 \% & 5.5 \% \
2002 & 68.3 \% & 25.9 \% & 5.8 \%
\end{array}
\end{array}$$

Accepted Answer

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

Question 10

Provide an appropriate response.
-Suppose that you want to construct a graph to represent the following data. $$\begin{array} { l | c } 
\text { Blood Type } & \text { Frequency } \
\hline \mathrm { O } & 90 \
\mathrm {~A} & 84 \
\mathrm {~B} & 18 \
\mathrm { AB } & 8
\end{array}$$ If you are primarily interested in the number of people in each category as a percentage of
the total number of people, would a bar chart or a pie chart be more useful? Explain your
thinking.

Accepted Answer

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

Question 11

Use the graph to answer the question.
-This double-bar graph shows the number of male (M)and female (F)athletes at a university over a four-year period.  Compare the trend in the number of male athletes during the four-year period and the trend in the
Number of female athletes during the four-year period .
A)The number of male athletes and the number of female athletes increased steadily over the four-year period.
B)The number of male athletes increased steadily over the four-year period. The number of female athletes increased in 1987 then decreased again in 1988 and 1989.
C)The number of male athletes increased steadily over the four-year period. The number of female athletes increased to a peak in 1988 and then decreased again in 1989.
D)The number of female athletes increased steadily over the four-year period. The number of male athletes increased to a peak in 1988 and then decreased again in 1989.

Accepted Answer

The answer of Use the graph to answer the question.
-This...

Question 12

State whether you think that the variables have strong positive correlation, weak positive correlation, strong negativecorrelation, weak negative correlation, or no correlation.
-The age of a computer and its value.
A)Strong positive correlation
B)No correlation
C)Weak negative correlation
D)Strong negative correlation
E)Weak positive correlation

Accepted Answer

The age of a computer and its value typically have a strong negative correlation because as a computer gets older, its value tends to decrease significantly.

Question 13

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 population by year for various countries. Population is given in
millions. $$\begin{array} { c | c | c | c } 
& \text { U.S. } & \text { Brazil } & \text { India } \
\hline 1950 & 152.3 & 53.4 & 369.9 \
1960 & 180.7 & 71.7 & 445.9 \
1970 & 205.1 & 95.7 & 555.0 \
1980 & 227.7 & 123.0 & 687.0 \
1990 & 250.1 & 151.1 & 841.7 \
2000 & 282.3 & 175.6 & 1002.7
\end{array}$$

Accepted Answer

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

Question 14

Provide an appropriate response.
-Explain in your own words the difference between a bar graph and a histogram. Give an
example of data for which you might use a histogram and an example of data for which
you might use a bar graph.

Accepted Answer

The answer of Provide an appropriate response.
-Explain in your own...

Question 15

Provide an appropriate response.
-Construct a frequency table and the corresponding histogram in which the following
conditions are satisfied:
- The frequency for the second class is twice the frequency of the first class
- In the histogram, the area of the bar corresponding to the second class is four times the
area of the bar corresponding to the first class

Accepted Answer

The answer of Provide an appropriate response.
-Construct a frequency table...

Question 16

Provide an appropriate response.
-The ages of employees of a company are summarized in the frequency table. $\begin{array} { l | c } 
\text { Age } & \text { Frequency } \
\hline 18 - 24 & 11 \
25 - 31 & 38 \
32 - 38 & 35 \
39 - 45 & 27 \
46 - 52 & 22 \
53 - 59 & 14 \
60 - 66 & 5
\end{array}$

A)

B)

C)

D) None of the above

Accepted Answer

The answer of Provide an appropriate response.
-The ages of employees...

Question 17

Provide an appropriate response.
-Suppose that a histogram is constructed for the frequency table shown below: $$\begin{array} { c | c } 
\text { Age } & \text { Frequency } \
\hline 30 - 39 & 11 \
40 - 49 & 23 \
50 - 59 & 17 \
60 - 69 & 12 \
70 - 89 & 6
\end{array}$$ The class 60-69 has twice the frequency of the class 70-89. In the histogram, will the area
of the bar for the class 60-69 be twice the area of the bar for the class 70-89? In other
words, will areas be proportional to frequencies in this histogram? Explain your thinking.
Are there any conditions under which areas are proportional to frequencies in histograms?

Accepted Answer

The answer of Provide an appropriate response.
-Suppose that a histogram...

Question 18

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 19

Use the graph to answer the question.
- Mike decides to buy shares of companies X and Y, which were initially selling for the same
price. The changes in the value of each stock over a 90-day period are shown in the graph
above. Describe the trend in the value of each stock over the 90-day period.

Accepted Answer

The answer of Use the graph to answer the question.
-...

Question 20

Construct the specified histogram.
-In a survey, 20 voters were asked their age. The results are summarized in the frequency
table below. Construct a histogram . $$\begin{array} { c | c } 
\text { Age } & \begin{array} { c } 
\text { Number of } \
\text { voters }
\end{array} \
\hline 20 - 29 & 5 \
30 - 39 & 5 \
40 - 49 & 6 \
50 - 59 & 0 \
60 - 69 & 4
\end{array}$$

Accepted Answer

The answer of  Construct the specified histogram.
-In a survey,...

Quiz 5: Statistical Reasoning

Use the guidelines to evaluate the study. Discuss flaws that you see in the study. -A TV show announced that their survey had revealed that 87% of Americans would rather be free than rich.

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.

State whether you think that the variables have strong positive correlation, weak positive correlation, strong negativecorrelation, weak negative correlation, or no correlation. -The age of a computer and its value.

Provide an appropriate response. -Explain in your own words the difference between a bar graph and a histogram. Give an example of data for which you might use a histogram and an example of data for which you might use a bar graph.

Use the graph to answer the question. - Mike decides to buy shares of companies X and Y, which were initially selling for the same price. The changes in the value of each stock over a 90-day period are shown in the graph above. Describe the trend in the value of each stock over the 90-day period.