Page 88 - Statistics for Dummies

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Part II: Number-Crunching Basics
So how much money does the typical NBA player make? One way to answer
this is to look at the average (the most commonly used statistic of all time).
The average, also called the mean of a data set, is denoted . The formula for
finding the mean is:
where each value in the data set is denoted by an x with a subscript i that
goes from 1 (the first number) to n (the last number).
Here’s how you calculate the mean of a data set:
1. Add up all the numbers in the data set.

2. Divide by the number of numbers in the data set, n.

The mean I discuss here applies to a sample of data and is technically called
the sample mean. The mean of an entire population of data is denoted with the
Greek letter μ and is called the population mean. It’s found by summing up
all the values in the population and dividing by the population size, denoted
N (to distinguish it from a sample size, n). Typically the population mean is
unknown, and you use a sample mean to estimate it (plus or minus a margin of
error; see all the details in Chapter 13).
For example, player salary data for the 13 players on the 2010 NBA Champion
Los Angeles Lakers is shown in Table 5-2.
Table 5-2 Salaries for L.A. Lakers
NBA Players (2009–2010)
Player Salary ($)
Kobe Bryant 23,034,375
Pau Gasol 16,452,000
Andrew Bynum 12,526,998
Lamar Odom 7,500,000
Ron Artest 5,854,000
Adam Morrison 5,257,229
Derek Fisher 5,048,000
Sasha Vujacic 5,000,000
Luke Walton 4,840,000

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