题目4.已知D(X)=4,D(Y)=1,ρ_(XY)=0.6,则D(3X-2Y)=()。A. 40;B. 34;C. 25.6;D. 17.64.已知D(X)=4,D(Y)=1,ρ_{XY}=0.6,则D(3X-2Y)=()。A. 40;B. 34;C. 25.6;D. 17.6题目解答答案C. 25.6;