举一反三
- Read this letter and fill in the gaps with the words from the box.
- 已知随机变量X的分布列如下:[img=386x130]17e43ec4c459e73.png[/img],则E(X)= A: 17/30 B: m未知,无法求出 C: -30/17 D: -17/30
- X,Y相互独立,X服从参数为2的泊松分布,Y服从[img=54x25]1803b4181e39f0c.png[/img],则[img=84x25]1803b4182602fd0.png[/img]与[img=86x25]1803b4182e0ab99.png[/img]分别为 A: -1,-7 B: 1, -7 C: 1,17 D: -1, 17
- 智慧职教: Directions: Fill in the blanks with the capitalized letter before the words like A, B, C or D.
- This is Cooper Preedy’s resume. Read and fill in the blanks with the proper words or information from the box.[img=1252x341]17e44862d4f0a87.png[/img][img=1220x466]17e44862e177cf5.png[/img][img=1208x416]17e44862ee4b610.png[/img][img=1210x468]17e44862faf0a21.png[/img][img=1218x466]17e448630797e1c.png[/img]
内容
- 0
设投掷1颗骰子的点数为X,则( ) 未知类型:{'options': ['E(X)=3.5,D(X)= [img=29x21]17e43c3db9dc21b.png[/img]', ' E(X)=3.5, D(X)= [img=22x41]17e43c3dc2146ee.png[/img]', ' E(X)=3.5,D(X)=3.5', ' E(X)=3.5,D(X)=[img=22x41]17e43c3dcacf7d1.png[/img]'], 'type': 102}
- 1
设X~U(a,b), a>;0,E(X)=3, D(X)=[img=15x41]17e438378e5b7d7.png[/img], 则P(1<;X<;3)=____。
- 2
设X~U(a,b), a>;0,E(X)=3, D(X)=[img=15x41]17e0a8afbe72bb4.png[/img], 则P(1<;X<;3)=____。
- 3
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].
- 4
设X为随机变量,若数学期望E(X)存在,则数学期望E(E(X))=__________。 A: E(X) B: 0 C: [img=51x27]18038f919d83a08.png[/img] D: [img=63x27]18038f91a6f0476.png[/img]