• 2022-06-09
    设总体X的分布律为P(X=0)=θ, P(X=1)=P(X=2)=(1-θ)/2,其中0<θ<1为待估未知参数。设[img=101x23]1802d3c6e1c13c2.png[/img]是简单随机样本。令[img=114x27]1802d3c6e985317.png[/img],[img=17x22]1802d3c6f1a9682.png[/img]为[img=101x23]1802d3c6e1c13c2.png[/img]中0所占的比例, 则以下哪个说法正确的?‍
    A: [img=17x22]1802d3c702e42ee.png[/img]比[img=17x22]1802d3c70bb0618.png[/img]更有效
    B: [img=17x22]1802d3c70bb0618.png[/img]和[img=17x22]1802d3c702e42ee.png[/img]都是[img=9x19]1802d3c72407a68.png[/img]的相合估计‍
    C: [img=17x22]1802d3c70bb0618.png[/img]比[img=17x22]1802d3c702e42ee.png[/img]更有效
    D: [img=17x22]1802d3c70bb0618.png[/img]是相合估计, [img=17x22]1802d3c702e42ee.png[/img]不是相合估计
    E: [img=17x22]1802d3c70bb0618.png[/img]不是相合估计, [img=17x22]1802d3c702e42ee.png[/img]是相合估计
    F: [img=17x22]1802d3c70bb0618.png[/img], [img=17x22]1802d3c702e42ee.png[/img]都不是相合估计
    G: [img=242x46]1802d3c7710420a.png[/img]
  • A,B

    举一反三

    内容

    • 0

      设随机变量(X,Y)在区域{(x,y): 0<|y|< x <2}内均匀分布,则以下结果正确的是 A: 当0<x<2时,[img=96x25]1802dded7db6eef.png[/img]. B: E(X)=4/3 C: 当0<|y|<2时,[img=105x45]1802dded872b92f.png[/img]. D: P(X<1)=0.5 E: 当0<x<2时,[img=110x45]1802dded915de6e.png[/img]. F: E(X)=2/3 G: 当0<y<2时,[img=95x43]1802dded9a54300.png[/img].

    • 1

      设X1,X2,X3是来自总体X的简单随机样本,则下列统计量[img=551x43]1803da166a9817a.png[/img]中, 是总体均值的无偏估计量. A: [img=17x22]1803da167310a8f.png[/img]和[img=17x22]1803da167bae41e.png[/img] B: [img=17x22]1803da168407eae.png[/img]和[img=17x22]1803da168b8a567.png[/img] C: [img=17x22]1803da167bae41e.png[/img]和[img=17x22]1803da168b8a567.png[/img] D: [img=17x22]1803da167310a8f.png[/img],[img=17x22]1803da167bae41e.png[/img]和[img=17x22]1803da168b8a567.png[/img]

    • 2

      设X1,X2,X3是来自总体X的简单随机样本,则下列统计量[img=551x43]18033806cb7d6a4.png[/img]中, 是总体均值的无偏估计量. A: [img=17x22]18033806d402a81.png[/img]和[img=17x22]18033806dc38d57.png[/img] B: [img=17x22]18033806e4e5857.png[/img]和[img=17x22]18033806eda0c27.png[/img] C: [img=17x22]18033806dc38d57.png[/img]和[img=17x22]18033806eda0c27.png[/img] D: [img=17x22]18033806d402a81.png[/img],[img=17x22]18033806dc38d57.png[/img]和[img=17x22]18033806eda0c27.png[/img]

    • 3

      设X1,X2,X3是来自总体X的简单随机样本,则下列统计量[img=551x43]1803da1393f5fdf.png[/img]中, 是总体均值的无偏估计量. A: [img=17x22]1803da139b3128e.png[/img]和[img=17x22]1803da13a44f014.png[/img] B: [img=17x22]1803da139b3128e.png[/img]和[img=17x22]1803da13b5b84de.png[/img] C: [img=17x22]1803da13a44f014.png[/img]和[img=17x22]1803da13b5b84de.png[/img] D: [img=17x22]1803da13d1416f1.png[/img],[img=17x22]1803da13a44f014.png[/img]和[img=17x22]1803da13b5b84de.png[/img]

    • 4

      设X1,X2,X3是来自总体X的简单随机样本,则下列统计量[img=551x43]18035733a7a3c92.png[/img]中, 是总体均值的无偏估计量. A: [img=17x22]18035733b1e4eac.png[/img]和[img=17x22]18035733badf839.png[/img] B: [img=17x22]18035733c3a1aec.png[/img]和[img=17x22]18035733cbc1913.png[/img] C: [img=17x22]18035733badf839.png[/img]和[img=17x22]18035733cbc1913.png[/img] D: [img=17x22]18035733b1e4eac.png[/img],[img=17x22]18035733badf839.png[/img]和[img=17x22]18035733cbc1913.png[/img]