# SCM 200 Manchester College Statistics Questions

Description

SCM 200
Chapter 2 Homework
Exercise 2.1
3. A survey asked chief executives at leading U.S. firms the following question: “Where do you
expect the US economy to be 12 months from now?” A representative sample of their responses
appears below:
Same
Same
Same
Worse
Same
Same
Same
Better
Same
Same
Same
Better
Same
Same
Same
Better
Same
Better
Same
Better
Worse
Worse
Same
Worse
Same
a. Construct frequency and relative frequency distributions that summarize the responses to
the survey. Where did most chief executives expect the U.S. economy to be in 12 months?
b. Use Excel to construct a pie chart and a bar chart to summarize your results.
10. A 2010 poll conducted by NBC asked respondents who would win Super Bowl XLV by 2011.
The responses by 20,825 people are summarized in the following table.
Team
Atlanta Falcons
New Orleans Saints
Houston Texans
Dallas Cowboys
Minnesota Vikings
Indianapolis Colts
Pittsburgh Steelers
New England Patriots
Green Bay Packers
Others
4,040
1,880
1,791
1,631
1,438
1,149
1,141
1,095
1,076
a. How many responses were for “Others”?
b. The Green Bay Packers won Super Bowl XLV, defeating the Pittsburgh Steelers by the score
of 31-25. What proportion of respondents felt that the Green Bay Packers would win?
c. Construct a bar chart for these data using relative frequencies.
Exercise 2.2
15. Consider the following data set:
4
3
8
10
9
8
8
8
4
7
5
5
6
7
5
10
6
12
11
10
12
14
3
3
13
11
8
14
11
8
a. Construct a frequency distribution using classes of 3 up to 5, 5 up to 7, etc.
b. Construct relative frequency, cumulative frequency, and cumulative relative frequency
distributions.
c. How many of the observations are at least 7 but less than 9? How many of the observations are
less than 9?
d. What percentage of the observations are at least 7 but less than 9? What percentage of the
observations are less than 9?
e. Graph a relative frequency histogram.
f. Graph an ogive.
18. Consider the following frequency distribution:
Class
1000 up to 1100
1100 up to 1200
1200 up to 1300
1300 to 1400
Frequency
2
7
3
4
a. Construct a relative frequency distribution. What percentage of the observations are at least
1100 but less than 1200?
b. Construct a cumulative frequency distribution and a cumulative relative frequency distribution.
How many of the observations are less than 1300?
c. Graph a frequency histogram.
23. The number of text messages sent by 25 13-year olds over the past month are as follows:
630
817
744
516
760
793
892
715
852
643
605
504
627
975
562
510
888
670
937
912
685
909
952
654
701
a. Construct a frequency distribution using classes of 500 up to 600, 600 up to 700, etc.
b. Construct the relative frequency, cumulative frequency, and cumulative relative frequency
distributions.
c. How many of the 13-year olds sent at least 600 but less than 700 text messages? How many
sent less than 800 messages?
d. Construct a polygon. Comment on the shape of the distribution.
26. The following relative frequency distribution summarizes the ages of women who had a child in the
last year.
Ages
15 up to 20
20 up to 25
25 up to 30
30 up to 35
35 up to 40
40 up to 45
Relative Frequency
0.10
0.25
0.28
0.24
0.11
0.02
a. Assume the relative frequency distribution is based on a sample of 2,000 women. Construct the
corresponding frequency, cumulative frequency, and cumulative relative frequency
distributions.
b. What percent of the women were at least 25 but less than 30 years old? What percent of the
women were younger than 35 years old?
c. Construct a relative frequency polygon. Comment on the shape of the distribution.
d. Construct an ogive. Using the graph, approximate the age of the middle 50% of the distribution.
Exercise 2.4
44. Construct a scatterplot with the following data. Does a linear relationship exist between x and y?
X
Y
10
3
4
2
6
6
3
6
7
4
46. In order to diversify risk, investors are often encouraged to invest in assets whose returns have
either a negative relationship or no relationship. The annual return data on two assets is shown in the
accompanying table (on the next page)
Return A
-20%
-5%
18
15
-12
Return B
8%
5
-1
-2
2
Construct a scatterplot. For diversity purposes, would the investor be wise to include both of these
assets in her portfolio? Explain.
SCM 200
Chapter 1 Supplemental Homework
1.
Go to www.finance.yahoo.com/ to get a current stock quote for Google Inc. (ticker symbol=GOOG).
Then, click on historical prices to record the monthly adjusted close price of Google stock in 2010. Create
a table that uses this information. What type of data do these numbers represent? Comment on the
data.
2.
Another good source of data is the U.S. Census Bureau. Go to www.census.gov/ and extract the most
recent median household income for Alabama, Arizona, California, Florida, Georgia, Indiana, Iowa,
Maine, Massachusetts, Minnesota, Mississippi, New Mexico, North Dakota, and Washington. What type
of data do these numbers represent? Comment on the regional differences in income.
3.
Which of the following variables are qualitative and which are quantitative? If the variable is
quantitative, then specify whether the variable is discrete or continuous.
a. Colors of cars in a mall parking lot.
b. Time it takes each student to complete a final exam.
c. The number of patrons who frequent a restaurant.
4.
In each of the following scenarios, define the type of measurement scale.
a. A kindergarten teacher marks whether each student is a boy or a girl.
b. A ski resort records the daily temperature during the month of January
c. A restaurant surveys its customers about the quality of its waiting staff on a scale of 1 to 4, where 1 is
poor and 4 is excellent.
5. A professor records the majors of her 30 students as follows
Accounting
Management
Marketing
Finance
Economics
Accounting
Economics
Finance
Finance
Undecided
Accounting
Economics
Undecided
Marketing
Marketing
Management
Management
Management
a. What is the measurement scale of these data?
b. Summarize the results in tabular form.
c. What information can be extracted from the data?
Finance
Economics
Accounting
Undecided
Undecided
Accounting
Management
Management
Finance
Economics
Economics
Economics