If the variance of x1, X2, X3 is 2, then the variance of data 2x1-1, 2x2-1, 2x3-1 is ()

If the variance of x1, X2, X3 is 2, then the variance of data 2x1-1, 2x2-1, 2x3-1 is ()

four
The data are added and subtracted at the same time, the variance remains unchanged, the data are multiplied and divided at the same time, and the data are multiplied and divided at the same time

Given that the variance of X1 + x2 + X3 is 3, then the variance of data 2x1 + 5, 2x2 + 5, 2x3 + 5 is?

The variance is 12
The variance of x1, X2, X3,..., xn is m
The variance of ax1 + B, AX2 + B, AX3 + B,. Axn + B is a square × M
So 4 × 3 = 12
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If the variance of data x1, X2,. Xn is 3, then the standard deviation of 2 (x1-3), 2 (x2-3)... 2 (xn-3) is 0

From the definition of variance, we can know that if we subtract or add the same number to each number of a group of data, the mean, variance and standard deviation will not change. If each number is multiplied by the same number n, the variance will be the original n & # 178; times. So the standard deviation is root 12 = 2 root 3