1. CONT…
Calculate the coefficient of variation
CV=SD
µ
SD =0.50709 AND SD =1.192037
₁ ₂
µ =7.2 AND µ =7.325
₁ ₂
CV =0.50709 X 100% AND CV =1.92037 X 100%
₁ ₂
7.2 7.325
CV =7.04% AND CV =26.22%
₁ ₂
NOTE; A higher CV indicates greater variability relative to mean.
A lower CV indicates less variability relative to the mean.
2. USES OF COEFFICIENT OF VARIATION
1. Comparing risk or volatility
In finance used to compare the risk (standard deviation) of different investment
relative to their expected returns. A lower CV indicates a better risk-return
trade-off
2.Comparing Variability Across Datasets
When comparing datasets with different units or scales (e.g comparing variability
in test scores vs income), CV standardizes the comparison.
3. Quality Control
In manufacturing, CV helps assess consistency or variability in production
process. A lower CV means more consistent product quality.
4. MEANING
Coefficient of variation is a type of relative measure of dispersion expressed
as a ratio of standard variation to the mean OR
Is a statistical measure of a relative variability of a data set. It is defined as
the ratio of standard deviation to the mean often expressed as a percentage.
CV=STANDARD DEVIATION (∂) X 100%
MEAN (µ)
Where standard deviation = √VARIANCE
VARIANCE= (X-µ)²
N
5. EXAMPLES 1
1.Business product sales
Product A
Mean monthly sales = 1000 units
Standard deviation = 100 units
CV = (100/1000) X 100 =10%
Product B
Mean monthly sales = 500 units
Standard deviation = 150 units
CV = (150/500) X 100 = 30%
Interpretation; Product A has more consistent sales than Product B
6. EXAMPLE 2
STORE 1 STORE 2
6.5 4.2
6.7 5.4
6.8 6.2
7.2 7.7
7.3 7.7
7.4 8.4
7.8 9.2
7.9 9.8