The question is :
$X_1,...,X_n$ are i.i.d.$Uniform(0,\theta)$. Let $X_{(n)}$ denote the maximum of these $n$ random variables. Prove that $\frac{X_1}{X_{(n)}}$ and $X_{(n)}$ are independent.
What I have now is that I can prove $X_{(n)}$ is the minimal sufficient statistic, but I do not know how to relate this to the proof of independence. Any suggestions?
Oh the answer is that , $\frac{X_1}{X_{(n)}}$ is an ancillary sufficient statistic, and we also can prove that $X_{(n)}$ is complete sufficient statistic. So by Basu's Lemma we conclude independence.