Its a full chapter of central tendency. you will learn all everything easily from this slide .so let`s learning.............

1. W E A R E F R O M
I N N O V A T O R S G R O U P
Welcome to our presentation

2. Our Group Members
S.N Name ID
1. Azizur Rahman (L) B-130202140
2 Izaz Ahmed B-130202118
3. Sheikh Rubel Hossain B-130202184
4. Sahidur Rahman Himel B-130202196
5. Shafikur Rahman B-130202182
6. Md. Rafiqul Islam B-130202120
7. Razib Chakma B-130202134
8. Afsana Aziz Priya B-130202180
9. Nurunnahar Sweety B-130202170
10. Md. Sujan Miah B-130202189

3. What is Central Tendency
 In statistics, a central tendency (or, more commonly, a measure of central
tendency) is a central or typical value for a probability distribution. It may also
be called a center or location of the distribution
 The term central tendency refers to the "middle" value or perhaps a typical
value of the data, and is measured using the mean, median, or mode. Each of
these measures is calculated differently, and the one that is best to use depends
upon the situation.

4. Measures of central tendency
There are many measures are available in central tendency. But all
of them are not so much important and popular. From them three
measures are very popular and important. They are
 Mean
 Median
 Mode

5. MERITS AND DEMERITS OF MEAN
MERITS OF ARITHMETIC MEAN :
1. Defined by algebraic formula.
2. Easy to calculate and simple to understand.
3. Based on all observations.
4. Widely used in statistical analysis.
DEMERITS OF ARITHMETIC MEAN:
1. Cannot be determined by inspection or by graphical location.
2. Cannot be computed for qualitative data .
3. Cannot be computed when class intervals have open ends.

6. MERITS AND DEMERITS OF Median
MERITS OF MEDIAN:
1. Simplicity
2. Possible even when data is incomplete
3. Certainty
4. Graphical presentation
DEMERITS OF MEDIAN:
1. Unrealistic
2. Lack of algebraic treatment

7. MERITS AND DEMERITS OF Mode,
MERITS OF MODE:
1. Simple and popular
2. Graphically presentation
3. Best representative
DEMERITS OF MODE:
1. Uncertain
2. Not capable of algebraic treatment

8. Why arithmetic mean is called the best measure
of central tendency
Easy to understand
Simple to compute
Dependency
Properly defined
Popularity
Usefulness
Less limitation

9. Uses of mean, median and mode
1. Arithmetic mean:
 It is used in computation of index number.
 It is used in time series analysis and sampling also.
2. Median:
 It is used in case of quantitative and qualitative data.
 It is used in case of time series and index number.
3. Mode:
 Choice of the customers can be measured by using
mode.
 It can be used for qualitative data.

10. Calculating Mean from Ungrouped Data
Methods: There are two way to calculate mean from
ungrouped data.
 1. Direct Method
 2. Short-Cut Method
Here =Arithmetic Mean
 N= Number of Observation
N
x
X


N
d
AX


X

11. Problem : Following information indicates the run of Shakib Al
Hasanfor last 8 test matches innings.
60, 78, 90, 99, 138, 35, 132, 67
What’s the average his run?
Now,
= 79
N
x
X


8
671323513899907860 


12. Calculation of Mean Value
S.L x d(x-a)
1 60 -30
2 78 -12
3 90 =A 0
4 99 9
5 138 48
N=5 d=15
Now,
=
= 93
N
d
AX


5
15
90

13. Calculation of arithmetic mean
 Calculation of Mean Value
 For grouped data, arithmetic mean may be computed
by applying any of the following method:
 1. direct method
 2. short-cut method
i
N
x
X 


N
fx
X



14. Problem
Following information indicates the score of 50
students in their business statistics course in their
last semester final
Marks range (C.I) No of Students (f)
40-50 10
50-60 20
60-70 5
70-80 5
80-90 5
90-100 5

15. Marks range
(C.I)
No of Students
(f)
x d fd
40-50 10 45 -2 -20
50-60 20 55 -1 -20
60-70 5 65=A 0 0
70-80 5 75 5 5
80-90 5 85 10 10
90-100 5 95 15 15

16. 63
10
50
10
65





 i
n
fd
Ax
Data Given,
A=65
N=50
i=10
fd=-10

17. 5.57
10
20
1025
50
10
20
10
2
50
50






Mediun

18.  LMode

19. Mode=