The document provides statistical analysis of marks data from 250 students of a class. It includes:
1) Calculation of measures of central tendency like arithmetic mean (39.4), median (41.27), and mode (41.23) from the raw marks data.
2) Construction of a frequency distribution table and associated graphs like bar graph and frequency polygon.
3) Calculation of measures of dispersion like variance (92.93) and standard deviation (9.64).
4) Mention of other statistical measures like skewness (-0.19553) and kurtosis to analyze the shape of the distribution.
2. Aim of the Presentation
The main aim of this presentation is to show the students, the use of
statistics in analyzing, presentation and making inferences from data in our
day to day life.
The raw data for this project includes the Marks of 250 students of a
class.
3. Acknowledgements
We would like to extend our heartiest regard to our mentor and teacher Dr.
Narinder Pushkarna or NP Sir who has guided us during the length and breadth
of this highly demanding work and always supporting us in every way he
could.
We would also like to thank our friends of Department of Statistics, Ramjas
College who helped us in finishing this extensive deal.
Aayush, Poorva, Shubham, Sahiba
5. Frequency Distribution
Inclusive type classification Exclusive type classification
Marks Number of students Marks Number of students
15-19 9 14.5-19.5 9
20-24 11 19.5-24.5 11
25-29 10 24.5-29.5 10
30-34 44 29.5-34.5 44
35-39 45 34.5-39.5 45
40-44 54 39.5-44.5 54
45-49 37 44.5-49.5 37
50-54 26 49.5-54.5 26
55-59 8 54.5-59.5 8
60-64 5 59.5-64.5 5
65-69 1 64.5-69.5 1
6. Associated Graphic
Representations
9
11 10
44 45
54
37
26
8
5
1
0
10
20
30
40
50
60
17 22 27 32 37 42 47 52 57 62 67
NumberofStudents
Class Marks
Bar Graph showing the marks of students
NO OF STUDENTS
7. Associated Graphic Representations
9
11 10
44 45
54
37
26
8
5
1
0
10
20
30
40
50
60
17 22 27 32 37 42 47 52 57 62 67
NumberofStudents
Class marks ( (u+l)/2 )
Frequency Polygon showing marks of students
NO OF STUDENTS
9. Arithmetic Mean
AM is sum of all observations divided by total number of
observations.
A.M. = 裡fixi / 裡fi
= 9930/250
CLASS MARKS NO OF STUDENTS fixi
17 9 153
22 11 242
27 10 270
32 44 1408
37 45 1665
42 54 2268
47 37 1739
52 26 1352
57 8 456
62 5 310
67 1 67
裡=250 裡=9930
10. Harmonic Mean
HM is sum of all observations divided by total number of
observations.
H.M. =1/[ (1/N)* 裡fi / xi]
=36.93
12. Median class ---- 34.5 39.5
Modal class ---- 39.5-44.5
Median = l + (N/2-CF) * h/f
=34.5 + (135-74)*5/45
=34.5 + 6.77 = 41.27
Mode = l + [h*(f1 - f0 )/ (2f1 - f0 f2 )]
=39.5 + [5*(54 - 45)/((2*54)-45-37)]
=39.5 + 1.73
=41.23
13. Variance and Standard Deviation
Quantitative data vary about a measure of central tendency and
these measures of deviations are called measures of dispersion or
variation.
Variance=(1/N)*裡fixi
2 -
[ (1/N)*裡fixi ] 2
= 92.93
Standard Variation =
sqt(variance) = 9.64
MARKS CLASS MARKS NO OF STUDENTS fixi fixi
2
14.5-19.5 17 9 153 2601
19.5-24.5 22 11 242 5324
24.5-29.5 27 10 270 7290
29.5-34.5 32 44 1408 45056
34.5-39.5 37 45 1665 61605
39.5-44.5 42 54 2268 95256
44.5-49.5 47 37 1739 81733
49.5-54.5 52 26 1352 70304
54.5-59.5 57 8 456 25992
59.5-64.5 62 5 310 19220
64.5-69.5 67 1 67 4489
Total 裡=250 裡=9930 裡=418870
14. Measure of Kurtosis and skewness
The measures of the direction and degree of asymmetry
are called measures of skewness.
The measures of the peakedness or flatness of the
frequency curves are called measures of kurtosis.
Skewness = -0.19553 ( as calculated from MS EXCEL )