更新1:
可唔可以教我有關圖片問題,要有步驟, 非常緊急!!!
pls help!!?
回答 (1)
2017-12-27 1:19 pm
Sol
(a)
(i)
0.2+0.3+0.15+0.25=0.9
P(X=2)=1－0.9=0.1
(ii)
EX=(－2)*0.2+1*0.15+2*0.1+5*0.25=1.2
(iii)
E(3x－2)=3EX－2=3.6－2=1.6
(iv)
EX^2=4*0.2+1*0.15+4*0.1+25*0.25=7.6
VarX=7.6－1.6^2=5.04
(b)
(i)
P=C(10，4)*0.15^4*0.85^6
(ii)
P=Σ(k=3 to 10)_C(10，k)*0.15^k*0.85^(10－k)
(c)
. ......１ ２ ３ ４ ５ ６
１ Ｙ Ｙ Ｙ Ｙ Ｙ Ｎ
２ Ｙ Ｎ Ｙ Ｎ Ｙ Ｎ
３ Ｙ Ｙ Ｙ Ｙ Ｙ Ｎ
４ Ｙ Ｎ Ｙ Ｎ Ｙ Ｎ
５ Ｙ Ｙ Ｙ Ｙ Ｎ Ｎ
６ Ｎ Ｎ Ｎ Ｎ Ｎ Ｎ
P=20/36=5/9
(a)
(i)
0.2+0.3+0.15+0.25=0.9
P(X=2)=1－0.9=0.1
(ii)
EX=(－2)*0.2+1*0.15+2*0.1+5*0.25=1.2
(iii)
E(3x－2)=3EX－2=3.6－2=1.6
(iv)
EX^2=4*0.2+1*0.15+4*0.1+25*0.25=7.6
VarX=7.6－1.6^2=5.04
(b)
(i)
P=C(10，4)*0.15^4*0.85^6
(ii)
P=Σ(k=3 to 10)_C(10，k)*0.15^k*0.85^(10－k)
(c)
. ......１ ２ ３ ４ ５ ６
１ Ｙ Ｙ Ｙ Ｙ Ｙ Ｎ
２ Ｙ Ｎ Ｙ Ｎ Ｙ Ｎ
３ Ｙ Ｙ Ｙ Ｙ Ｙ Ｎ
４ Ｙ Ｎ Ｙ Ｎ Ｙ Ｎ
５ Ｙ Ｙ Ｙ Ｙ Ｎ Ｎ
６ Ｎ Ｎ Ｎ Ｎ Ｎ Ｎ
P=20/36=5/9
收錄日期: 2021-04-30 22:35:50
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20171226132947AAjBl0y