If a set of data x1, X2 If the average of XN is 2 and the variance is 9, then the data are 2x1-3, 2x2-3 What are the average and variance of 2xn-3?
∵ a set of data x1, X2 X = 2, variance is S2 = 9, then another set of data 2x1-3, 2x2-3, 2x3-3 X ′ = 2 × 2-3 = 1, the variance is s ′ 2, ∵ S2 = 1n [(x1 -. X) 2 + (X2 -. X) 2 +] +(xn-.x)2]=9,∴S′2=1n[(2x1-1-2.x+1)2+(2x2...
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