This presentation is about graphical methods of determining Median and Mode, drawing of Histogram from unequal class

1. GRAPHICAL METHOD OF
DETERMINATION AND
REPRESENTATION
Dr. RITUPARNA GHOSH
ASSISTANT PROFESSOR OF GEOGRAPHY
RANIGANJ GIRLS’ COLLEGE

2. Draw a histogram and a frequency polygon on the basis of
the data given below:
HEIGHT(FEET) NO.OF TREES
0-7 26
7-14 57
14-21 92
21-28 134
28-35 216
35-42 287
42-49 341
49-56 360

4. Represent the data in the form of Histogram and determine Mode
from it
WEIGHT IN KG NO.OF STUDENTS
30-34 3
35-39 5
40-44 12
45-49 18
50-54 14
55-59 6
60-64 2

5. Convert the class limits into class boundaries and prepare a
separate table
CLASS LIMITS CLASS BOUNDARIES NO.OF STUDENTS
30-34 3
35-39 5
40-44 12
45-49 18
50-54 14
55-59 6
60-64 2

6. Convert the class limits into class boundaries and prepare a
separate table
CLASS LIMITS CLASS BOUNDARIES NO.OF STUDENTS
30-34 29.5-34.5 3
35-39 34.5-39.5 5
40-44 39.5-44.5 12
45-49 44.5-49.5 18
50-54 49.5-54.5 14
55-59 54.5-59.5 6
60-64 59.5-64.5 2

8. • Draw less than ogive to represent the following data and
determine median from it:
HEIGHT (CM) FREQUENCY
141-150 5
151-160 16
161-170 56
171-180 19
181-190 4
TOTAL 100

9. • SOLUTION
HEIGHT (CM) FREQUENCY HEIGHT
(CLASS
BOUNDARIES)
141-150 5 140.5-150.5
151-160 16 150.5-160.5
161-170 56 160.5-170.5
171-180 19 170.5-180.5
181-190 4 180.5-190.5
TOTAL 100

10. • SOLUTION
HEIGHT (CM) < CUMULATIVE FREQUENCY
140.5 0
150.5 0+5=5
160.5 0+5+16=21
170.5 0+5+16+56=77
180.5 0+5+16+56+19=96
190.5 0+5+16+56+19+4=100

12. • Draw ogives to represent the following data and determine
median from it:
HEIGHT (CM) FREQUENCY
141-150 5
151-160 16
161-170 56
171-180 19
181-190 4
TOTAL 100

13. • SOLUTION
HEIGHT (CM) FREQUENCY HEIGHT
(CLASS
BOUNDARIES)
141-150 5 140.5-150.5
151-160 16 150.5-160.5
161-170 56 160.5-170.5
171-180 19 170.5-180.5
181-190 4 180.5-190.5
TOTAL 100

14. WORKSHEET FOR LESS THAN AND MORE
THAN OGIVES
HEIGHT (CM) < CUMULATIVE
FREQUENCY
> CUMULATIVE
FREQUENCY
N
140.5 0 0+4+19+56+16+
5=100
100
150.5 0+5=5 0+4+19+56+16=
95
100
160.5 0+5+16=21 0+4+19+56=79 100
170.5 0+5+16+56=77 0+4+19=23 100
180.5 0+5+16+56+19=
96
0+4=4 100
190.5 0+5+16+56+19+
4=100
0 100

15. SCALE:
2CM=1 CLASS
BOUNDARY
1CM=10
CUMULATIVE
FREQUENCY

16. DRAWING OF HISTOGRAM FROM
UNEQUAL CLASSES
ANNUAL SALES NO .OF FIRMS
0-20 20
20-50 50
50-100 69
100-250 30
250-500 25
500-1000 19

17. SOURCE: STATISTICAL
METHODS (VOLUME I),
N.G. DAS)