Question

The distribution function of random variable is

(a) P(X less than or equal to x)

(b) P(X greater than or equal to x)

(c) P(X less than x)

(d) P(X greater than x)

I got this question in an international level competition.

I'd like to ask this question from Random Signals in portion Signals and Spectra of Digital Communications

Answer 1

The correct option is (a) P(X less than or equal to x)

Easiest explanation: The distribution function of a random variable is the probability that the value taken by the random variable is less than or equal to the real number x.