Post on 07-Aug-2015
transcript
WELLCOME
Measures of Center Tendency
What Is Measures of Center Tendency?
Measures of central tendency are numerical descriptive measures
which indicate or locate the center of a distribution or data set.
Types of Measures of Tendency :
Mean Meiden Mode
Arithmetic Mean Geometric Mean Weighted Mean
Mean
What Is Mean?
The Mean of a set of values or
measurements is the sum of all the
measurements divided by the number of
measurements in the set.
Arithmetic Mean
The arithmetic mean is the sum of a set of
observations,
positive, negative or zero, divided by the number
of observations.
Arithmetic Formula of MEAN
n
xx
n
in
1
Arithmetic Example
An electronics store sells CD players
at the following prices:
$350, $275, $500, $325, $100, $375, and $300.
What is the mean price?
$2225 / 7 = $317.86
The mean or average price of a CD player is $317.86.
What is Geometric Mean ?
The Geometric Mean is a special type of average
where we multiply the numbers together and then
take a square root (for two numbers), cube root
(for three numbers) etc.
Formula of Geometric Mean
n√(a1 × a2 × ... × an)
What is Weighted Mean ?
The weighted mean is a special case of arithmetic
mean. It occurs when there are several
observations of the same value.
Formula of Weighted Mean
n
ii
n
iii
w
xwx
1
1
Meiden
What Is Meiden ?
The Median is the middle value of a set of data.
Formula of Meiden (Ungroup) :
)1(2
1
n
e XMFor odd
1222
1nne XXMFor even
Formula of Meiden (group) :
Fn
f
iLM
ooe 2
Lower class boundary of the median Class
class interval
Frequency of the median class Cumulative
frequency
Mode
What is Mode ?
The Mode is the most frequently observed value in a data set.
Formula of Mode:
iLM
21
110
Slope Angle (°)
Frequency (f)
0-5 6
5-10 12
10-15 7
15-20 5
20-25 0
0Li
1
2
= Lower class boundary of modal class = Interval of modal class
= difference of frequency of modal class and class before modal class
= difference of frequency of modal class and class after modal class
0L
modal class which has highest frequency
Example :
The most frequently printed words in English are: the, of, and, a , and to.
ANY QUESTION ?
THANK YOU !!