Question

A random variable X has the following probability distribution
Find the expected value of x.

Answer 1

E(x)= sum(x*P(x))
= 5*(1/4) + 2*(1/2) +1(1/4)
=1.25 + 1 + 0.25
=2.5

Answer 2

Hi ,

We know that the expected value

of X is denoted by E( X ).

E( X ) = ( summation of X ) P( X )

= 5 × 1/4 + 2 × 1/2 + 1 × 1/4

= 5/4 + 1 + 1/4

= ( 5 + 4 + 1 )/4

= 10/4

= 2.5

Therefore ,

E( X ) = 2.5

I hope this helps you .

: )