The probability model for random variable X is specified as: P(X) = X/6 for X = 1, 2 or 3
The expected value of X is
A) 2.00
B) 0.50
C) 0.333
D) 2.333
E) 0.167

Question

Quizplus · Accepted Answer

The expected value of a discrete random variable X is given by E(X) = ∑[X * P(X)]
Using the probability model specified, we have:
E(X) = (1/6)*1 + (2/6)*2 + (3/6)*3
E(X) = 1/6 + 4/6 + 9/6
E(X) = 14/6
E(X) = 2.333
Therefore, the answer is D.

The Probability Model for Random Variable X Is Specified As