Known samples x1, X2 If the variance of XN is 2, then the sample is 3x1 + 2, 3x2 + 2 The variance of 3XN + 2 is______ .

Known samples x1, X2 If the variance of XN is 2, then the sample is 3x1 + 2, 3x2 + 2 The variance of 3XN + 2 is______ .

∵ samples x1, X2 If the variance of XN is 2, and each data in a set of data is expanded several times, the variance of the new data will be expanded by its square times The variance of 3XN is 32 × 2 = 18