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

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

2. MEDIAN FROM SIMPLE SERIES
• CALCULATE MEDIAN OF :
32, 22, 29, 17, 40, 26, 21
THE SERIES IS ODD I.E. ‘n’ IS 7
ARRANGE THE DATA IN ASCENDING ORDER
17, 21, 22, (26), 29, 32, 40
MEDIAN IS 26, IT IS THE MIDDLE MOST VALUE
IT CAN BE FOUND OUT BY OBSERVATION

3. MEDIAN FROM SIMPLE SERIES
• CALCULATE MEDIAN OF :
3.1, 2.6, 5.0, 4.7, 2.4, 3.9, 5.1, 3.6
THE SERIES IS EVEN I.E. ‘n’ IS 8
ARRANGE THE DATA IN ASCENDING ORDER
2.4, 2.6, 3.1, (3.6), (3.9), 4.7, 5.0, 5.1
MEDIAN = (3.6+3.9)/2 = 3.75

4. MEDIAN FROM
SIMPLE
FREQUENCY
DISTRIBUTION
SIZE FREQUENCY
4 40
5 48
6 52
7 57
8 60
9 63
10 57
11 55
12 50
13 52
14 41
15 57
16 63
17 52
18 48
19 40

5. SIZE FREQUENCY (f) CUMULATIVE
FREQUENCY (cf)
4 40 40
5 48 88
6 52 140
7 57 197
8 60 257
9 63 320
10 57 377
11 55 432
12 50 482
13 52 534
14 41 575
15 57 632
16 63 695
17 52 747
18 48 795
19 40 835

6. SIZE FREQUENCY (f) CUMULATIVE
FREQUENCY (cf)
4 40 40
5 48 88
6 52 140
7 57 197
8 60 257
9 63 320
10 57 377
11 (55) (432)
12 50 482
13 52 534
14 41 575
15 57 632
16 63 695
17 52 747
18 48 795
19 40 835
MEDIAN
RANK=(N+1)/2th
OBSERVATION
N= 835
MEDIAN RANK=
(835+1)/2= 418
MEDIAN VALUE =
11

7. MEDIAN FROM GROUPED FREQUENCY
DISTRIBUTION
MARKS NO. OF STUDENTS
15-25 4
25-35 11
35-45 19
45-55 14
55-65 0
65-75 2

8. MEDIAN FROM GROUPED FREQUENCY
DISTRIBUTION
MARKS NO. OF STUDENTS
(f)
cf
15-25 4 4
25-35 11 15
35-45 19 34
45-55 14 48
55-65 0 48
65-75 2 50 = N
TOTAL 50 = N =Σf

9. MEDIAN FROM GROUPED FREQUENCY
DISTRIBUTION
MARKS NO. OF
STUDENTS (f)
cf
15-25 4 4
25-35 11 15
(35-45) (19) (34)
45-55 14 48
55-65 0 48
65-75 2 50 = N
TOTAL 50 = N =Σf
MEDIAN RANK=
N/2TH
OBSERVATION
= 50/2 = 25TH
OBSERVATION
MEDIAN CLASS=
(35-45)

10. • MEDIAN VALUE=
• Where,
• l= lower class boundary
• h= class width of median class
• N/2= Median Rank
• f= frequency of the median class
• C= cumulative frequency of the class preceding the median class
l = 35
h= 10
N/2= 25
f= 19
C= 15
MEDIAN =
40. 26