Dsme

LEVIMN01_0131536893.QXD

2/25/05

3:33 PM

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Self-Test Solutions and Answers to Selected

Even-Numbered Problems

The following represent worked-out solutions to Self-Test Problems and brief answers to most of the even-numbered problems in the text.

For more detailed solutions including explanations, interpretations, and Excel and Minitab output, see the Student Solutions Manual.

CHAPTER 1

2.12 Stem-and-leaf of Finance Scores

1.2 Small, medium and large sizes are categories.

1.4 (a) The number of telephones is a numerical variable that is discrete

because the variable is counted. (b) The length of the longest longdistance call is a numerical variable that is continuous since any value

within a range of values can occur. (c) Whether there is a telephone line

connected to a computer modem in the household is a categorical variable

because the answer can only be yes or no. (d) Same answer as in (c).

1.6 (a) categorical; (b) numerical, continuous; (c) numerical, discrete;

(d) numerical, discrete.

1.8 (a) numerical, continuous; (b) numerical, discrete; (c) numerical,

continuous; (d) categorical.

1.10 The underlying variable, ability of the students, may be continuous

but the measuring device, the test, does not have enough precision to

distinguish between the two students.

1.26 (a) all U.S. households; (b) all people who have tried and quit online

banking; (c) categorical; (d) a statistic.

CHAPTER 2

2.3 (b) The Pareto diagram portrays the data best because it allows you to

focus on the categories that have the highest percentage of reasons.

(c) Try to avoid the following mistakes: little or no knowledge of the

company, unprepared to discuss career plans, and limited enthusiasm.

2.4 (b) The Pareto diagram is better than the pie chart to portray these

data because it not only sorts the frequencies in descending order, it also

provides the cumulative polygon on the same scale. (c) From the Pareto

diagram, it is obvious...