The Handy Math Answer Book

This is a compact way of
showing how the data values
are distributed between the
various number of people. It
allows us to see, at a glance,
the most “popular” number
(also called the “modal class”)
of people working in an office
for this building’s 10 offices—
in this case, a one-person
office. Such data can further
be visualized with the use of
bar charts, histograms, or pie
charts.

There are even more ways
to see the data from this fre-
quency table. We can also
illustrate this chart in terms
of percent. In particular, we
can say that 40 percent of the
offices contain 1 person, 20
percent have 2 people, 20 per-
cent have 3 people, and 20
percent have 4 people.

What is a percent?

A percent (using the symbol
%) is the ratio of one number
to another. Percents are quan-
titative terms in which nper-
cent of a number is none-
hundredths of the number;
they are usually expressed as the equivalent ratio of some number to the number 100.
For example, the ratio of 25 to 50 means the number 25 is 50 percent of 50. They are
not true numbers; thus, percents can’t be used in calculations, such as addition or
multiplication. But operations can be conducted with percents when they are translat-
ed into ratios and fractions, such as 25 percent is equal to 0.25 or 1/4.

265

APPLIED MATHEMATICS

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0.0

0.5

1.0

1.5

2.0

Here are four different types of charts used in statistics (from top

to bottom): a histogram, a bar graph, a pie chart, and a line graph

(statistics are not based on actual data here).