Question

Fill in the blank.

For a discrete random variable, the sum of the probabilities of its possible values equals ____.

Short answer

The sum of the probabilities of all discrete random variables equals 1.

Step-by-step solution

Given information

Take :

"The total of the probability of all possible values for a discrete random variable is equal to ___."

Solution

The total probability of all possible values for a discrete random variable is always 1. Consider the following random variable X, which can take one of two values: 1 or 2, with

$P(1)=0.3andP(2)=0.7.$P ( 1 ) = 0.3 and P ( 2 ) = 0.7.

in this case.

$P(1)+P(2)=1$

Because total likelihood resembles that one of the outcomes will occur, which is always true, the sum of the probabilities will always equal 1.