Page 83 - Statistics for Dummies

Chapter 5
Means, Medians, and More
In This Chapter
▶ Summarizing data effectively
▶ Interpreting commonly used statistics
▶ Realizing what statistics do and don’t say
very data set has a story, and if statistics are used properly, they do
Ea good job of uncovering and reporting that story. Statistics that are
improperly used can tell a different story, or only part of it, so knowing how
to make good decisions about the information you’re given is very important.
A descriptive statistic (or statistic for short) is a number that summarizes or
describes some characteristic about a set of data. In this chapter, you see
some of the most common descriptive statistics and how they are used, and
you find out how to calculate them, interpret them, and put them together
to get a good picture of a data set. You also find out what these statistics say
and what they don’t say about the data.

Summing Up Data with

Descriptive Statistics

Descriptive statistics take a data set and boil it down to a set of basic infor-
mation. Summarized data are often used to provide people with information
that is easy to understand and that helps answer their questions. Picture
your boss coming to you and asking, “What’s our client base like these
days, and who’s buying our products?” How would you like to answer that
question — with a long, detailed, and complicated stream of numbers that
are sure to glaze her eyes over? Probably not. You want clean, clear, and
concise statistics that sum up the client base for her, so that she can see how
brilliant you are and then send you off to collect even more data to see how
she can include more people in the client base. (That’s what you get for being
efficient.)

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