Q11 of 108 Page 33

Let x1, x2, ……xn be values taken by a variable X and y1, y2, …….yn be the values taken by a variable Y such that yi = axi + b, i = 1,2, …….,, n. Then,

we have given, yi=axi+b

Mean (Y) =



Mean (y) =


Then, Var(Y) =


And, Var(X) =






Hence, Var(Y) = a2 Var(X)

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