UPSC NDA Math Model Paper 5

Given: For some observations we have standard deviation and coefficient of variation as 1.2 and 25.6 respectively.
Here, we have to find the mean for the same observations.
Let mean be x
As we know, Coefficient of variation = =

standard deviaiton

Mean

×100
⇒ Coefficient of variation =

1.2

x

×100=25.6
⇒x=

1.2

25.6

×100
⇒ x = 4.69 (approximately)
Hence, option B is the correct answer.