Variance of the longer piece

A 11-metre rope is cut at a single uniformly random point, giving two pieces. Let LL be the length of the longer piece. Compute Var⁡(L)\operatorname{Var}(L).

Show hints (2)+
  1. L=max⁡(U,1−U)L=\max(U,1-U) lives in [12,1][\tfrac12,1]. Find its CDF there.
  2. It's Uniform(12,1)\text{Uniform}(\tfrac12,1); variance of a length-12\tfrac12 uniform is (1/2)2/12(1/2)^2/12.

Answer

Reveal answer →

0.0208 (± 0.001)

Create a free account to see the full worked solution and track your progress.

Interview format: Trading Aptitude Tests, Betting Game Rounds

Related questions