CA Foundation · Quantitative Aptitude · Measures of Central Tendency and Dispersion
A Surat textile unit reports that the monthly output of Machine P has a mean of 250 metres and a standard deviation of 30 metres. What is the coefficient of variation of Machine P's output?
The coefficient of variation is 12%. It is found by dividing the standard deviation of 30 by the mean of 250 and multiplying by 100, which gives a relative measure of dispersion expressed as a percentage of the average output.
- A8.33%
- B12%Correct
- C15%
- D20%
Explanation
CV = (SD / Mean) × 100 = (30 / 250) × 100 = 12%. The option 8.33% comes from inverting the ratio (mean/SD scaled wrongly, i.e. 250/30), and 15% and 20% do not follow from the data.
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