利用该样本信息估计总体均数95%可信区间,公式是

A、3.20±1.96×0.50
B、3.20±1.96×0.50/[img=~/QImg/2013-10-14-11-38-02/image081.gif]
C、3.00±1.96×0.50/[img=~/QImg/2013-10-14-11-38-02/image082.gif]
D、3.20±t0.05,11×0.50
E、3.20±t0.05,11×0.50/[img=~/QImg/2013-10-14-11-38-02/image083.gif]