Page 24 - Basic Statistics

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2. NUMERICAL MEASURES TO SUMMARIZE DATA

2.1 MEASURE OF CENTRAL LOCATION

There are four measures of central location that is often used, which are

the arithmetic mean, median, mode, and geometric mean. The selection of
which of one of the measures of central location are used, depending on the

natural of the data and purpose of measurement.

2.1.1 MEASURE OF CENTRAL LOCATION FOR UNGROUP DATA

a. Arithmetic Mean

For the data set X1, X2, ..., Xn. Expressed as the arithmetic mean (read: X

bar), defined as

n
 X i
X 1 + X 2 + . . . X + n i= 1
X = =
n n

Where,

X = Mean value

n = Number of observations

Worked Example 2.1 :

For the following data set, find the value of mean
2, 6, 6, 7, 3, 1, 3

Worked Solution :

Mean is

2 6 + 6 + 7 + 3 + 1 + 3 + 28
X = = = 4
7 7

~~* CHAPTER 2 NUMERICAL MEASURES TO SUMMARIZE DATA *~~