某职业联赛的总决赛在甲、乙两队之间角逐,采用七场四胜制,即有一队胜四场,则此队获胜,且比赛结束.在

2025-04-15 10:11:46
推荐回答(1个)
回答1:

(Ⅰ)门票收入为120万元的概率: P 1 =(
2
3
) 4 +(
1
3
) 4 =
17
81

(Ⅱ)ξ的可能取值为120,150,180,210.
P(ξ=120)=
17
81

P(ξ=150)=
C 34
(
2
3
) 3 (
1
3
2
3
+
C 34
(
1
3
) 3 (
2
3
1
3
=
8
27

P(ξ=180)=
C 35
(
2
3
) 3 (
1
3
) 2 ×
2
3
+
C 35
(
1
3
) 3 (
2
3
) 2 ×
1
3
=
200
729

P(ξ=210)=
C 36
(
2
3
) 3 (
1
3
) 3 ×
2
3
+
C 36
(
1
3
) 3 (
2
3
) 3 ×
1
3
=
160
729

ξ的分布列为: