Which of the following statements about a discrete random variable and its probability distribution is true?
A) Values of the random variable can never be negative.
B) Negative values of f(x) are allowed if ∑f(x) = 1.
C) Values of f(x) must be greater than or equal to zero.
D) The values of f(x) increase to a maximum point and then decrease.

Question

Quizplus · Accepted Answer

The values of f(x) must be greater than or equal to zero since probabilities cannot be negative. Choice A is incorrect because some discrete random variables, such as stock prices, can take on negative values. Choice B is incorrect because probabilities cannot be negative. Choice D is incorrect because there is no requirement for the values of f(x) to increase to a maximum and then decrease.

Which of the Following Statements About a Discrete Random Variable