# Exercises(Ch. _ 5)

Topics: Probability Pages: 12 (1582 words) Published: November 16, 2013
152

Ghapter 5

Exercises
Some people are in favor of reducing federal taxes to increase consumer spending and others are against it. Two persons are selected and their opinions are recorded. Assuming no one is undecided, list the possible outcomes.

2. A quality control inspector selects a part to be tested. The part is then declared acceptable, repairable, or scrapped. Then another part is tested. List the possible outcomes of this experiment regarding two parts. tGE

3. A.r."y of 54 students at the Wall College of Business showed the following majors: 1.

Accounting

10

Finance
Economics
Management

Marketing

5

3
6
10

Suppose you select a student and observe his or her maior.
a. What is the probability he or she is a management major?
b. Which concept of probability did you use to make this estimate? 4. A large company that must hire a new president prepares a final list of five candidates, all of whom are equally qualified. Two of these candidates are members of a minority group. To avoid bias in the selection of the candidate, the company decides to select the president

by lottery.

a. What is the probability one of the minority candidates is hired? b. Which concept of probability did you use to make this estimate? 5. ln each of the following cases, indicate whether classical, empirical, or subjective probability is used.

a. A baseball player gets a hit in 30 out of 100 times at bat. The probability is.3 that he gets a hit in his next at bat.

b. A seven-member committee of students

is formed to study environmental issues. What
is the likelihood that any one of the"seven is chosen as the spokesperson? c. You purchase one of 5 million tickets sold for Lotto Canada. What is the likelihood you will win the \$1 million jackpot?

d. The probability of an earthquake in northern California in the next 10 years above 5.0 on the Richter Scale is .80.
6. A firm will promote two employees out of a group of six men and three women. a. List the chances of this experiment if there is particular concern about gender equity. b. Which concept of probability would you use to esjimate these probabilities? 7. A sample of 40 oil industry executives was selected t&"tesJ a questionnaire. One question about environmental issues required a yes or no answer.

a. What is the experiment?
b. List one possible event.
c. Ten of the 40 executives responded yes. Based on these sample responses, what is the probability that an oil industry executive will respond yes? d. What concept of probability does this illustrate?

e. Are each of the possible outcomes equally likely and mutually exclusive? 8. A sample of 2,000 licensed drivers revealed the following number of speeding Number of

Violations

0
146
218
312
49
5 or more
Total
a. What is the experiment?
b. List one possible event.

Number of Drivers
1

,910

5

2,000

violations.

e)

r58

Chapter 5

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Routine physical examinations are conducted annually as part of a health service program for General Concrete lnc. employees. lt was discovered that 8 percent of the employees need corrective shoes, 15 percent need major dental work, and 3 percent need both corrective shoes and major dental work'

(4 What is the probability that an employee selected at random will needr either corrective shoes or major dental work?
(b) Show this situation in the form of a Venn diagram.

hxercrses
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frffi|M,,IJfi\$%BJili,1ft[:,ryt,"H*x1Iii,!";ftiij::i[?,;;3i,.i^,1I.?k":tHl1 will happen?

12. The events X and Y are mutually exclusive. Suppose

P(X)

:

.05 and PQi

:

.02. What is

the probability of either X or Y occurring? What is the probability that neither X nor Y will happen?

13. A study of 200 adverlising firms

revealed their income after taxes:

Taxes
million
Under \$1
\$1 million to \$20 million
\$20 million or more
lncome after

Number of Firms
102
61

37

is the probability an...