A set of data x1, X2 The average of XN is 90, the variance is 13.5, then 3x1-80, 3x2-80 The average of 3xn-80 is______ The variance is______ ． | Math enthusiast | Mathematical art

A set of data x1, X2 The average of XN is 90, the variance is 13.5, then 3x1-80, 3x2-80 The average of 3xn-80 is The variance is ．

∵x1、x2… The average number of XN is 90, ∧ (x1, X2 xn）÷n=90∴（3x1-80，3x2-80… 3xn-80）÷3=3×90-80=190，∵x1、x2… The variance of XN is 13.5, ｜ 3x1-80, 3x2-80 The variance of 3xn-80 is 3 × 3 × 13.5 = 121.5

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