Question

Which of the following is a valid probability distribution for a discrete random variable? Check all that apply.

A. 1/2, 1/4, 1/8, 1/16, 1/32, 1/64, 1/128, 1/128
B. 1/5, 1/10, 1/10, 1/10, 1/5, 1/10, 1/10, 1/10
C.1/6, 1/6, 1/6, 1/6, 1/6, 1/6
D.1/3, 1/4, 1/5, 1/6
E.-1/2, -1/3, -1/4, -1/5, 137/60

Answer 1

the sum of probabilities should equal one

Answer 2

also, probabilities should not be negative