一组数据x1,x2,x3,x4,x5的平均数是2,有（x1+x2+x3+x4+x5）/2=5,x1+x2+x3+x4+x5=10,3x1+2+3x2+2+3x3+2+3x4+2+3x5+2=3(x1+x2+x3+x4+x5)+5*2=40(3x1+2+3x2+2+3x3+2+3x4+2+3x5+2)/5=8另一组数据3x1+2,3x2+2,3x3+2,3x4+2,...