Question

State the following are not the probability distributions of a random variable. Give reasons for your answer.

Z	3	2	1	0	-1
P(Z)	0.3	0.2	0.4	0.1	0.05

Answer 1

It is known that the sum of all the probabilities in a probability distribution is one.

Sum of the probabilities = 0.3 + 0.2 + 0.4 + 0.1 + 0.05 = 1.05 ≠ 1

Therefore, the given table is not a probability distribution of random variables.