Question

If 40 is added to each of a set of 25 values, the Coefficient of Variation changes to 40% and if it is subtracted from each value, the Coefficient of Variation rises to 80%. What is the mean and standard deviation of the set of 25 values?

(a) Mean= 120; SD = 74
(b) Mean= 120; SD=64
(c) Mean= 130; SD =64
(d) None ​

Answer 1

If 40 is added to each of a set of 25 values, the Coefficient of Variation changes to 40% and if it is subtracted from each value, the Coefficient of Variation rises to 80%. What is the mean and standard deviation of the set of 25 values?

(a) Mean= 120; SD = 74

(b) Mean= 120; SD=64

(c) Mean= 130; SD =64

(d) None

αηѕωєя:-

The coefficient of variation (CV) is defined as the ratio of the standard deviation to the mean:

CV has to be a ratio and not a percentage for the above formula. So, 40% would be 0.4 as a ratio.

SD would be 0.4 * 5 = 2

Answer 2

Answer:

CORRECT OPTION IS B

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