Copyright © 2008, The McGraw-Hill Companies, Inc.
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Topics Key Ideas, Formulas, and Techniques Examples
Charts and
Graphs, p. 608- Charts and graphs are used to summarize and
illustrate statistical data. - Pie charts are used to illustrate how different
parts make up a whole. - Bar and column charts compare different
categories. - Line charts illustrate how a quantity changes
over time. - Follow instructions given in text to create these
by using Excel.
See the examples in Section 16.1.Mean and
Median, p. 617- The mean is calculated by adding up all the
values and dividing by the number of values. - Mean is usually what people mean by
“average.” - Median is found by listing the values in order
and selecting the middle value, or if there are
two middle values, by fi nding their mean. - Mean is affected by unusually high or low
values, median is not.
A cell phone manufacturer is testing
the time that a new phone can be used
before the battery must be recharged. The
company takes six phones, brings them up
to full charge, and then tests to see how
long the charges last with the phone in
use. The times for each of the phones (in
minutes) are 408, 348, 386, 420, 468, and- Find the mean and median time.
(Example 16.2.1)
Weighted
Averages, p. 618- A weighted average counts some values more
heavily than others. - Multiply each value by its weight and add up the
total. - Divide by the total of the weights.
Suppose that a computer services
company has fi ve part-time workers. Each
worker’s hourly wage and number of hours
worked in a typical week are listed in the
table below. Calculate (a) the mean of the
hourly rates, (b) the median, and (c) the
weighted average, weighted by hours
worked.
(Example 16.2.2)Indexes, p. 620 • Indexes are used to measure the overall cost or
value of something.- To use comparative indexes, multiply by the
ratio of the indexes.
Suppose that you look up a cost-of-
living index for Boston and fi nd that it is
1,184.29. You also know that the index for
Fort Wayne is 939.25 .What salary would
be needed in Boston to match $35,000 in
Fort Wayne.
(Example 16.2.4)Expected
Relative
Frequency and
Expected Value,
p. 622- The expected relative frequency is the percent
or fraction of the time that a particular event is
predicted to occur. - The expected frequency is the number of times
the event is predicted to happen. - Expected frequency (expected relative
frequency)(number of chances). - Expected cost (expected relative
frequency)(cost per occurrence).
A minor league baseball events promoter
is offering a promotion at an upcoming
game. One fan will be randomly chosen
from the stands and given the opportunity
to bat against the team’s ace pitcher. If the
fan hits a home run before accumulating
three strikes, he will win $50,000.
From past experience of similar events,
the promoter believes that such a fan will
win the prize 1 out of every 1,250 times
the promotion is run. Calculate (a) the
expected relative frequency of the fan
winning and (b) the expected prize for this
promotion.
(Example 16.2.5)CHAPTER 16
SUMMARY(Continued)