Question

From the given random variable table, the value of a is
(a) 1
(b) 1/2
(c) 4
(d) 1/4

Answer 1

We have to use the concepts that
$\bold{\Sigma{P(X=x)=1}}$
e.g., P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) ...... = 1

Given,
P(X = 0) = a
P(X = 1) = 2a
P(X = 2) = a
So, P(X = 0) + P(X = 1) + P(X = 2) = 1
a + 2a + a = 1
4a = 1
a = 1/4

Hence, option (d) is correct.