题目
5.在以下总体的数学期望μ的无偏估计中,最优估计是-|||-(A) dfrac (1)(3)(X)_(1)+dfrac (1)(3)(X)_(2)+dfrac (1)(3)(X)_(3) . (B) dfrac (1)(2)(X)_(1)+dfrac (1)(2)(X)_(2)-|||-(C) dfrac (1)(2)(X)_(1)+dfrac (1)(3)(X)_(2)+dfrac (1)(6)(X)_(3) . (D) dfrac (1)(2)(X)_(1)+dfrac (1)(4)(X)_(2)+dfrac (1)(4)(X)_(3)
题目解答
答案
D. $\dfrac {1}{2}{X}_{1}+\dfrac {1}{4}{X}_{2}+\dfrac {1}{4}{X}_{3}$