Q2 of 40 Page 944

Coefficient of variation of the two distributions are 60% and 80% respectively, and their standard deviations are 21 and 16 respectively. Find their arithmetic means.

Given: Coefficient of variation of two distributions are 60% and 80% respectively, and their standard deviations are 21 and 16 respectively.


Need to find: Arithmetic means of the distributions.


For the first distribution,


Coefficient of variation (CV) is 60%, and the standard deviation (SD) is 21.


We know that,


⇒


⇒


⇒


⇒


For the first distribution,


Coefficient of variation (CV) is 80%, and the standard deviation (SD) is 16.


We know that,


⇒


⇒


⇒


⇒


Therefore, the arithmetic mean of 1st distribution is 35 and the arithmetic mean of 2nd distribution is 20.


More from this chapter

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8

The mean and standard deviations of a group of 100 observations were found to be 20 and 3 respectively. Later on it was found that three observations 21, 12 and 18 were incorrect. Find the mean and standard deviation if the incorrect observations were omitted.

 1

The following results show the number of workers and the wages paid to them in two factories F1 and F2.

Which factory has more variation in wages?


 3

The mean and variance of the heights and weights of the students of a class are given below:


















Heights



Weights



Mean



63.2 inches



63.2 kg



SD



11.5 inches



5.6 kg



Which shows more variability, heights or weights?


 4

The following results show the number of workers and the wages paid to them in two factories A and B of the same industry.

(i) Which firm pays a larger amount as monthly wages?


(ii) Which firm shows greater variability in individual wages?