Part (a): The following table givesthe probability distribution of the random va
ID: 2953033 • Letter: P
Question
Part (a):
The following table givesthe probability distribution of the random variable X, the numberof foreign tours a minister make in a year.
X
1
2
3
4
5
P(X)
0.1
0.2
0.3
0.3
0.1
Find the probabilitythat:
i) Minister makes visitbetween 2 and 5 (both exclusive)
ii) Minister makes at themost 4 tours
Part(b):
The range of the random variable X is [0, 1, 2, 3, x], where xis unknown. If each value is equally likely and the mean of X is 6,determine x.
Part(c):
Show that the following function satisfies the properties of ajoint probability mass function.
X Y f(x,y)
-1 -2 1/8
-0.5 -1 1/4
0.5 1 1/2
1 2 1/8
Also determine E(X) and E(Y)
X
1
2
3
4
5
P(X)
0.1
0.2
0.3
0.3
0.1
Explanation / Answer
i) Minister makes visit between 2 and 5 (both exclusive)
P(2<X<5)=P(X=3)+P(X=4)=0.3+0.3=0.6
ii) Minister makes at the most 4 tours
P(X<=4)=1-P(X=5)=1-0.1=0.9
Show that the following function satisfies the properties of ajoint probability mass function.
X Y f(x,y)
-1 -2 1/8
-0.5 -1 1/4
0.5 1 1/2
1 2 1/8
Also determine E(X) and E(Y)