Question

7) A random variable X takes values. O, 1, 2, 3,
and its mean is 1.3, if P(x = 3) = 3P (X= 1),
and P(X=2) =0.3, then P(X = 0) is
a) 0.1
b) 0.42
c) 0.3
d) 0.4​

Answer 1

Answer:

d 0.4

Step-by-step explanation:

E[X]=∑

i=0

3

x

i

p

i

=0∗P(X=0)+1∗P(X=1)+2∗P(X=2)+3∗P(X=3)=1.3

1∗P(X=1)+2∗0.3+3∗2∗P(X=1)=1.3

P(X=1)=0.1

Nowusing

∑

i=0

3

p

i

=1=P(X=0)+P(X=1)+P(X=2)+P(X=3)

P(X=0)+0.1+0.3+0.2=1

P(X=0)=0.4