I'm having a lot of trouble with this question:

Find for the uniform random variable distribution. Compare with the corresponding probabilistic statement given by Chebyshev's theorem and the empirical rule.

according to the solution in the book the answer is 1; I have no idea what this number represents.

The variance of a uniform distribution is so in this case it should be . This is where I get stuck, plus I don't think that I'm even going in the right direction. Any help would be appreciated.