Classically, if a particle is not observed, the probability per unit length of finding it...

Classically, if a particle is not observed, the probability per unit length of finding it in a box is a constant I/L along the entire length of the box. With this, show that the classical expectation value of the position is ½L, that the expectation value of the square of the position is⅓L2, and that the uncertainty in position is  .