The document discusses different measures of central tendency including the mean, median, and mode. It explains that the mean is calculated by summing all the values and dividing by the number of observations. The median involves arranging the data and selecting the middle value for odd numbers of observations or averaging the two middle values for even numbers of observations. Measures of central tendency are used to identify the central or typical value in a data set.

1. •The sample mean, used to estimate the population mean µ, is computed as
If N is odd, the median position equals
, and the value of the
Chapter 3: Measures of Central Tendency and Location
, where n is the number of observations in the sample.
Summation
The sample mean, used to estimate the
population mean µ, is computed as
The first step in calculating the median, denoted by Md, is to arrange the data
in an array.
If N is odd,
If N is even,

2. Chapter 3: Measures of Central Tendency and Location
Measures of Central Tendency
In statistics, an average is a measure of
central tendency. It is a single number that can
represent a set of data. There are three kinds
of averages, namely: mean, median and mode.
A measure of central tendency is any single
value that is used to identify the “center” of the
data or the typical value. It is often referred to
as the average.

3. Chapter 3: Measures of Central Tendency and Location
The Arithmetic Mean
The most common average and sometimes simply
referred to as the mean.
The sum of all the values of the observations divided by
the number of observations.
The mean for a finite population with N
elements, denoted by the Greek letter µ (mu).