The average value of data x 1, x2, x3, x4 and x5 is 2, and the variance is one third, then the average value of another set of data 3x 1-2, 3x2-2 and 3x3-2 ... 3x5-2 is equal to 3x2-2 = 4.

The variance is 3.2×1/3 = 3.

The change of average value is consistent with the change of data.

Addition and subtraction have no effect on variance, and the variance is twice the original square when multiplying and dividing.