Question

Find the Arithmetic mean if the coefficient of variation of 20 observations is (125/3) % and the sum of squares of the deviations of these observations
Pick ONE option
12
O 13
O 15
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Answer 1

Answer:

the arithmetic mean if the

Answer 2

Answer:

given that n= 20

let the mean be x¯x¯

individual observation xixi

variance be σ2σ2 that is 5

now, as we know that,

x¯=∑xinx¯=∑xin

σ2=∑(xi−x¯)2n=1n⋅∑x2i−(x¯)2σ2=∑(xi-x¯)2n=1n⋅∑xi2-(x¯)2

now let the new observation is yi=k⋅xiyi=k⋅xi and no of observation is n

now, y¯=∑yin=∑(k⋅xi)n=k⋅∑xiny¯=∑yin=∑(k⋅xi)n=k⋅∑xin

σ2y=∑(yi−y¯)2n=∑(k⋅xi−k⋅x¯)2n