(1)根据题意可得:X的可能取值为4、5、6.
所以P(X=4)=
=
C
C
1 15
P(X=5)=
=
C
C
C
8 15
P(X=6)=
=
C
C
C
6 15
属于X的分布列为:
P | 4 | 5 | 6 | ||||||
X |
|
|
|
1 |
15 |
8 |
15 |
6 |
15 |
16 |
3 |
1 |
3 |
2 |
3 |
1 |
3 |
2 |
3 |
C |
1 |
3 |
2 |
3 |
1 |
3 |
2 |
3 |
2 |
3 |
44 |
729 |
44 |
729 |