3. LEARNING OBJECTIVES
• The aim of the chapter is to make students to
understand Measures of Skewness, Karl Pearson
Co-efficient of Skewness and Bowley's Co-efficient
of skewness
4. LEARNING OUTCOMES
• After this Unit The Students can be able to apply to
Sample Population Data by Differentiating Normal
and Abnormal Distributions with regard to
Dispersion & Skewness.
5. SESSION - 55
• Bowely's Co-efficient of Skewness Under Continuous
Series Problems----------------------------02
6. Bowley’s Co-efficient of Skewness
In Karl Pearson method of measuring skewness the
whole of the series is needed. Prof. Bowley has
suggested a formula based on position of quartiles. In
symmetric distribution quartiles will be equidistance
from the median. Q2 – Q1 = Q3 – Q2 , but in skewed
distributions it may not happen. Hence
Q3 + Q1 – 2Median OR Q2
SK = Q3 – Q1
7. CONTD
Calculate Bowley’s co efficient of skewness, Ex;1
ANS; Q3 + Q1 – 2Median OR Q2
SK = Q3 – Q1
To compute quartiles, Qj class = (Nth/4) item
11. CONTD
Ex; 2, Find out Bowley's coefficient of skewness :
ANS; the above data is given in inclusive method, we
should convert into exclusive method by the help of
correction factor. Ex, Lower limit of Second Class is 70 &
Upper limit of first Class is 60.
Correction Factor = 70 – 60/ 2
Correction Factor = 0 .5
Subtract CF in all lower limits and add to all upper limits,
we get, SEE IN NEXT SLIDE
15. SUMMARY
As we already discussed and learnt today on skewness
as below
• Bowely's Co-efficient of Skewness Under Continuous
Series Problems----------------------------02
16. MCQs
1 .The distribution in sum of Q3+Q1= 44,Q3–Q1= 16 and
median = 21, Bowley skewness
a) 0.125
b) Positive skewed
c) Negative skewed
d) None of these
2. formula of Bowley’s of skewness
a) SK = Q3+ Q1 – 2median/ Q3 – Q1
b) Negatively skewed
c) Symmetrical
d) None of these
17. MCQs
3 . If mean = 36.31 and Mode = 32 and S.D =15.8 then
Karl Pearson co efficient of skewness is
a) 0.27
b) Different
c) Zero
d) None of these
4. If mean = 36.31 and Mode = 32 and Karl Pearson co
efficient of skewness is 0 .27, S.D =?
a) Positive Skewed
b) Negative Skewed
c) 15.8
d) None of these
18. MCQs
5 . The values of mean, median and mode can be
a) Some time equal
b) Never equal
c) Always equal
d) None of these
20. REFERENCES
• S.P. Gupta, Sultan Chand and Sons Publications, 2017
• S. C. Gupta, Himalaya Publishing House,
Fundamentals of Statistics, 2018
• R.S.N Pillai and Bagavathi, S.Chand publications, 2010