Random Variable & Expected Value

Random Variable

A random variable is a function that assigns a real number to each outcome of an experiment.

 

Expected Value

 

Suppose  the random variable x can take on the n values x₁,x₂,x₃,……..x_n.

Also, suppose the probabilities that values occur are, respectively,

P₁.P₂,……….P_n. Then the expected value of the random variable is

E(x) = x₁ p₁ + x₂p₂+……..x_np_n.