Question

Which of the following can be the probability distribution of a random variable ?

• A.

  $X$	1	2	3
  $P(X)$	-0.5	0.5	0.1

• B.

  $X$	1	2	3	$4$	$5$
  $P(X)$	$0.1$	$0.4$	$0.05$	$-0.2$	$0.2$

• C.

  $X$	$1$	$2$	$3$	$5$
  $P(X)$	$0.2$	$0.3$	$0.2$	$0.2$

• D.

  $X$	$0$	$1$	$2$
  $P(X)$	$0.4$	$0.2$	$0.4$

Answer 1

Answer: (D)

$X$	$0$	$1$	$2$
$P(X)$	$0.4$	$0.2$	$0.4$

Answer 2

The correct option is (D):