CA Foundation · Quantitative Aptitude · Measures of Central Tendency and Dispersion
A series has mean 40 and coefficient of variation 25%. Every observation is increased by 10. What is the new coefficient of variation?
The new coefficient of variation is 20%. The original standard deviation is 10, which does not change when a constant is added, but the mean rises from 40 to 50. So CV becomes 10 divided by 50, times 100, equal to 20%.
- A20%Correct
- B25%
- C30%
- D12.5%
Explanation
Original SD = 25% of 40 = 10. Adding a constant leaves the SD unchanged at 10, while the mean becomes 50. New CV = 10/50 × 100 = 20%. The option 25% wrongly assumes CV is unaffected by a shift.
Did you get it right without looking?
One question tells you little. A timed set on Measures of Central Tendency and Dispersion shows your real accuracy, how long you take and where you lose marks.
More Measures of Central Tendency and Dispersion questions
- The monthly sales of a Surat textile shop have a mean of ₹50,000 and a standard deviation of ₹7,500. What is the coefficient of variation of…
- The mean of 8 observations is 25. If one observation, recorded as 18, is found to be actually 34, what is the correct mean?
- A variable x has mean 20 and standard deviation 4. A new variable is defined as y = 3x − 5. The mean and standard deviation of y are respect…
- For the following grouped data on monthly electricity bills (₹) of 60 households, find the mode using the interpolation formula. Class 0-200…
- The marks of 10 students have a range of 40 and the smallest mark is 20. If every mark is increased by 10% and then 5 marks are added, what …
- In a distribution of 60 observations, the median class is 20-30 with frequency 18, and the cumulative frequency of the class preceding it is…