# Expected Value

Discussion in 'Probability' started by Rueful Rabbit, Dec 18, 2011.

1. ### Rueful RabbitGuest

Hi All,

The side of a cube is of length U. U ~ U(0,1)

What is the expected value of the volume?

Now,
V = U^3
E[V] = Integral from 0 to 1 of V.f(u) du

= Integral from 0 to 1 of U^3 . 1 du

Why is f(u) = 1 here?

Rueful.

Rueful Rabbit, Dec 18, 2011

2. ### Rueful RabbitGuest

I know now ...

For the uniform distribution ...

f(x) = 1/(b-a) = 1/1 = 1

I was too quick to post.

Rueful Rabbit, Dec 18, 2011