Chapter 5 (5.4): Practice Problem
Q.
Forty percent of the business travelers carry either a cell phone or a
laptop (
USA Today
, September 12, 2000). In a sample of 15
business travelers,
a.
What is the probability that three have a cell phone or a laptop?
b. What is the probability that 12 of the travelers have neither a cell phone
nor a laptop?
c.
What is the probability that at least three of the travelers have a
cell phone or a laptop?
d.
Find the expectation and variance of the number of business travelers
having a cell phone or a laptop.
e.
Change “forty percent” to “seventy percent” in the problem. Find
the probability that five have either a cell phone or a laptop. (do it
by using the table.)
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View Full DocumentChapter 6 (6.2): Practice Problems
Q1.
According to a survey, subscribers to
The Wall Street Journal Interactive
Edition
spend an average of 27 hours per week using the computer at work
(
WSJ.com
Subscriber Study, 1999). Assume the normal distribution applies and
that the standard deviation is 8 hours.
a.
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 Fall '08
 Priya
 Normal Distribution, Standard Deviation, Variance, Bureau of Labor Statistics, cell phone, USA Today

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