In IFOA paper 19 April 2012, Q.1. The following 24 observations give the length of time (in hours, ordered) for which a specific fully charged laptop computer will operate on battery before requiring recharging. 1.2 1.4 1.5 1.6 1.7 1.7 1.8 1.8 1.9 1.9 2.0 2.0 2.1 2.1 2.1 2.2 2.3 2.4 2.4 2.5 3.1 3.6 3.7 4.5 The owner of this computer is about to watch a film on his fully charged laptop. Calculate from these data the longest showing time for a film that he can watch, so that the probability that the battery's lifetime will be sufficient for watching the entire film is 0.75. I ended up calculating third quartile. The answer showed, we got to calculate first quartile. http://imgur.com/zXZ9c4V -- Is it because, the longer the movie time is, lesser the battery life would become? Can somebody clarify?
If you took third quartile,say,movie time=2.45, then only 25% battery's lifetime will be sufficient for watching the entire film. But you need 75%
