This presentation will help to learn the process of calculation of Mean from different types of data

1. MEAN- A MEASURE OF
CENTRAL TENDENCY
Dr. RITUPARNA GHOSH
ASSISTANT PROFESSOR OF GEOGRAPHY
RANIGANJ GIRLS’ COLLEGE

2. MEAN FROM SIMPLE SERIES
• CALCULATE MEAN OF THE DAILY INCOME OF
10 FAMILIES:
18, 20, 35, 55, 38, 54, 100, 85, 37, 53
TO OBTAIN THE MEAN
ADD ALL THE GIVEN VALUES AND DIVIDE IT BY
THE NUMBER OF OBSERVATIONS
MEAN= Rs 49.5

3. MEAN FROM SIMPLE FREQUENCY
DISTRIBUTION
TYPE OF WORKERS RATE OF WAGES PER
WORKERS (Rs)
NO. OF WORKERS
MECHANIC 2.50 2
FITTER 3.50 14
ELECTRICIAN 4.00 20
CARPENTER 3.00 7
SMITH 3.00 6
CLERK 2.00 1

4. MEAN FROM SIMPLE FREQUENCY
DISTRIBUTION
TYPE OF
WORKERS
RATE OF WAGES
PER WORKERS
Rs (x)
NO. OF
WORKERS (f)
fx
MECHANIC 2.50 2 5
FITTER 3.50 14 49
ELECTRICIAN 4.00 20 80
CARPENTER 3.00 7 21
SMITH 3.00 6 18
CLERK 2.00 1 2
TOTAL(Σ) 50= N=Σf 175= Σfx
MEAN (AVERAGE RATE OF WAGES PER WORKER)= Σfx/Σf=
175/50 = Rs 3.50

5. MEAN FROM GROUPED FREQUENCY
DISTRIBUTION
AGE (YEARS) NO. OF EMPLOYEE
18-21 8
22-25 32
26-35 54
36-45 36
46-55 20

6. MEAN FROM GROUPED FREQUENCY
DISTRIBUTION
AGE IN YEARS
(X)
NO. OF
EMPLOYEE (f)
Mid Value (x) fx
18-21 8 19.5 156
22-25 32 23.5 752
26-35 54 30.5 1647
36-45 36 40.5 1458
46-55 20 50.5 1010
TOTAL(Σ) 150= N=Σf 5023= Σfx
MEAN (AVERAGE AGE IN YEARS)= Σfx/Σf= 5023/150=
33.49 YEARS